Answers
I hope this helps!
Answer:
-9.25 in decimal form
-9 1/4 :) in fraction form
hope this helps here is the explanation on how I got this answer :)!
therefor it will be the last answer :)
Step-by-step explanation:
-9.25
= – 9.25 × 100
1 × 100= –925
100
= – 925 ÷ 25
100 ÷ 25
= – 374
= – 9 1/4
Related Questions
the solution of the equation x2-6x=0 is ?
Answers
find the value of x. Pregunta matemática
Answers
Answer:
Ejercicios Resueltos
ANGULOS
1. Si el complemento de ángulo x es 2x, ¿Cuál es el valor de x en
grados?
Solución:
2x x 90 += °
3x 90
x 90 / 3
x 30
= °
= °
= °
2. Si el suplemento del ángulo x es 5x, ¿Cuál es el valor de x?
Solución:
5x+x=180
6x=180
x=180 /6
x=30
°
°
°
°
3- Determínese los dos ángulos x e y, cuya suma es 90 y cuya
diferencia es 10 .
°
°
Solución:
-Planteamos el sistema de ecuaciones:
x y 90
x y 10
+= °
−= °
-Resolvemos el sistema. Mediante el método de suma y resta
obtenemos:
2x 100
x 100 / 2
x 50
= °
= °
= °
-Hacemos la sustitución del valor encontrado de x en la primera
ecuación: 50 y 90
y 90 50
y 40
°+ = °
= °−
= °
°
∴La solución al problema es x 50 , y 40 =°= °
°
4. Hállense dos ángulos complementarios tales que su diferencia sea
30° .
Solución:
-Planteamos el sistema de ecuaciones:
x y 90
x y 30
+= °
−= °
-Resolvemos el sistema. Mediante el método de suma y resta
obtenemos:
2x 120
x 120 / 2
x 60
= °
= °
= °
-Hacemos la sustitución del valor encontrado de x en la primera
ecuación:
60 y 90
y 90 60
y 30
°+ = °
= °−
= °
∴La solución al problema es x 60 , y 30 = °= °
°
5. Hállense dos ángulos suplementarios tales que el uno sea 20 mayor
que el otro.
°
Solución:
-Planteamos el sistema de ecuaciones:
x y 180
x y 20
+= °
=+ °
-Resolvemos el sistema:
(y 20 ) y 180
2y 180 20
2y 160
y 80
+ °+ =
= °− °
= °
= °
-Hacemos la sustitución del valor encontrado de y en la primera
ecuación: x 80 180
x 180 80
x 100
+ °=
= °−
= °
°
°
∴La solución al problema es:
x = °= ° 100 , y 180
TRIANGULOS
1.- ¿Cuánto miden cada uno de los ángulos interiores del siguiente
triángulo?
Solución:
Nota: La suma de los ángulos interiores de los triángulos es
180° .
((( A B C 180 ++= °
3x 5x 4x 180 ++ = °
12x 180 = °∴( ( (( A 22.5 , B 52.5 , C 30 , CBR 127.5 = ° = ° =° = °
x 15 = °
∴( ( A 45 , B 75 ,C 60 =° =°= °
°
°
°
°
°
°
2.- ¿Cuánto miden cada uno de los ángulos del siguiente triángulo?
Solución
a) Ángulo extendido
( ( B CBR 180 + = Esto debido a que son ángulos suplementarios
(B 15x 60 180 + − °=
(B 180 60 15x = °+ °−
(B 240 15x = °−
b) Suma de los ángulos interiores del triángulo
((( A B C 180 ++=
3x (240 15x) 4x 180 + °− + =
7x (240 15x) 180 + °− =
− + °= 8x 240 180− =− 8x 160°
x 7.5 =
∴( ( (( A 22.5 , B 52.5 , C 30 , CBR 127.5 = ° = ° =° = °
3.- Escribe la definición de bisectriz del triángulo.
Es la semirrecta que biseca el ángulo, es decir, divide el ángulo
en dos ángulos congruentes.
4.- ¿Qué es la mediatriz de un triángulo?
La mediatriz de un lado de un triángulo (y en general de un
segmento de recta), es la recta perpendicular a ese lado en su
punto medio.
5.- ¿Que es la mediana de un triángulo?
La mediana de un triángulo, es el segmento de la recta que une
un vértice con el punto medio del lado opuesto.
CUADRILATEROS
1.- ¿Qué cuadrilátero tiene las dos diagonales iguales y sus lados son
iguales dos a dos?
Rectángulo
2.- Si los ángulos de un cuadrilátero miden, respectivamente, 80º, 110º
y 70º, ¿Cuánto medirá el ángulo que falta?
100º
3.- ¿Cuál es el paralelogramo que tiene las diagonales perpendiculares?
Rombo
4.- ¿Cómo se llama el cuadrilátero que tiene dos lados paralelos?
Trapecio
5.- Encuentra el área del paralelogramo que tiene 5cm de base y 3 de
altura
A b*a
A 5*3
A 15
=
=
=
POLÍGONOS 1.- Cuatro ángulos interiores de un pentágono valen respectivamente
110°, 90°, 85° y 125°. ¿Cuánto vale el quinto ángulo?
Solución:
Si la suma de los ángulos interiores de un polígono es:
180°*(n-2)=180°*(5-2) = 540°, a lo que le se le resta los
valores de los ángulos que se dieron, consecuentemente, el
quinto ángulo vale 130°.
2.- ¿Cuántos lados tiene, en cada caso, el polígono cuyos ángulos
interiores suman respectivamente 1080°, 900°, 1260°?
Solución:
Despejando de la fórmula el valor de n, tenemos que:
. 2
180
suma angulos n = ° + , y esto aplicado a cada valor de la suma de los
ángulos internos, obtenemos que los valores de n son 8, 7 y 9
respectivamente.
3.- ¿Cuánto vale cada ángulo exterior de un octágono regular?
Solución:
Aplicando el teorema de que la suma de los ángulos exteriores
de un polígono es 360°, entonces cada ángulo exterior vale
360°/8 = 45°
4.- Calcular los ángulos exteriores de un triángulo rectángulo que tiene
un ángulo agudo doble del otro.
Solución:
Se tiene que la suma de los ángulos interiores es
180°*(n-2)= 180° y éste a su vez es igual a 90° + x + 2x,
despejando x de 3x = 90°, x= 30°, entonces los ángulos
interiores son 30°, 60° y 90°, teniendo como ángulos exteriores
150°, 120° y 90°.
Step-by-step explanation:
g A report on the nightly news broadcast stated that 10 out of 108 households with pet dogs were burglarized and 20 out of 208 without pet dogs were burglarized. Suppose that this data is used to test the claim that the proportion of households with dogs that are burglarized is the same as the proportion of households without dogs that are burglarized. What would be the test statistic for this test
Answers
Answer:
Test statistic |Z| = 0.1040 < 1.96 at 0.05 level of significance
Step-by-step explanation:
Step(i):-
Given that a report on the nightly news broadcast stated that 10 out of 108 households with pet dogs were burglarized
First proportion
[tex]p_{1} = \frac{x_{1} }{n_{1} } = \frac{10}{108} = 0.0925[/tex]
Given that a report on the nightly news broadcast stated that 20 out of 208 households without pet dogs were burglarized
Second proportion
[tex]p_{2} = \frac{x_{2} }{n_{2} } = \frac{20}{208} = 0.0961[/tex]
where
[tex]P = \frac{n_{1}p_{1} +n_{2}p_{2} }{n_{1} +n_{2} }[/tex]
P = 0.09486
Q = 1 - P = 1 - 0.09486 = 0.90514
Step(ii):-
Test statistic
[tex]Z = \frac{p_{1}-p_{2} }{\sqrt{PQ(\frac{1}{n_{1} } +\frac{1}{n_{2} } )} }[/tex]
[tex]Z = \frac{0.0925-0.0961 }{\sqrt{0.09486 X 0.90514(\frac{1}{108 } +\frac{1}{208 } )} }[/tex]
Z = -0.1040
|Z| = |-0.1040|
|Z| = 0.1040
Critical value Z = 1.96 at 0.05 level of significance
Please help thank you so much Bobby is creating a banner for the homecoming parade. The banner consists of an isosceles triangle, a rectangle, and a semicircle. He wants to add sparkling lights around the trim of the banner.
What is the total length of sparkling lights he can add to the banner?
Answers
Answer:
total length =5+5+10+10+π(10/2)=45.71ft.
Perimeter of semicircle
πr8/2π4π12.56ftNow
Total length
3+5+8+10+10+12.56-836+4.5640.56ftA fast food restaurant executive wishes to know how many fast food meals teenagers eat each week. They want to construct a 80% confidence interval with an error of no more than 0.07. A consultant has informed them that a previous study found the mean to be 5.8 fast food meals per week and found the standard deviation to be 1.3. What is the minimum sample size required to create the specified confidence interval
Answers
Answer:
The minimum sample size required to create the specified confidence interval is of 565.
Step-by-step explanation:
We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:
[tex]\alpha = \frac{1 - 0.8}{2} = 0.1[/tex]
Now, we have to find z in the Ztable as such z has a pvalue of [tex]1 - \alpha[/tex].
That is z with a pvalue of [tex]1 - 0.1 = 0.9[/tex], so Z = 1.28.
Now, find the margin of error M as such
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.
Found the standard deviation to be 1.3.
This means that [tex]\sigma = 1.3[/tex]
Error of no more than 0.07. What is the minimum sample size required to create the specified confidence interval?
This is n for which M = 0.07. So
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
[tex]0.07 = 1.28\frac{1.3}{\sqrt{n}}[/tex]
[tex]0.07\sqrt{n} = 1.28*1.3[/tex]
[tex]\sqrt{n} = \frac{1.28*1.3}{0.07}[/tex]
[tex](\sqrt{n})^2 = (\frac{1.28*1.3}{0.07})^2[/tex]
[tex]n = 565.1[/tex]
Rounding up:
The minimum sample size required to create the specified confidence interval is of 565.
Please solve these systems of equations by substitution.
1. x+y=7
x+2y=11
2. x+y=22
x+2y=48
3. x+y=45
x+2y=36
Answers
Step-by-step explanation:
x+ 2(7-x) = 11
x+14-2x = 11
-x = -3
x = 3
3+ y = 7
y = 4
x + 2(22-x) = 48
x + 44 -2x = 48
-x = 4
x = -4
-4 + y = 22
y = 26
y = 45-x
x + 2(45-x) = 36
x + 90 -2x = 36
-x = 54
x = -54
-54 + y = 45
y = 99
Answer:
1. x=3 and y=4
2. x=−4 and y=26
3. x=54 and y=−9
Step-by-step explanation:
1. x+y=7;x+2y=11
Step: Solvex+y=7for x:
x+y+−y=7+−y(Add -y to both sides)
x=−y+7
Step: Substitute −y+7 for x in x+2y=11:
x+2y=11
−y+7+2y=11
y+7=11(Simplify both sides of the equation)
y+7+−7=11+−7(Add -7 to both sides)
y=4
Step: Substitute 4 for y in x=−y+7:
x=−y+7
x=−4+7
x=3(Simplify both sides of the equation)
2. x+y=22;x+2y=48
Step: Solve x+y=22 for x:
x+y+−y=22+−y(Add -y to both sides)
x=−y+22
Step: Substitute−y+22 for x in x+2y=48:
x+2y=48
−y+22+2y=48
y+22=48(Simplify both sides of the equation)
y+22+−22=48+−22(Add -22 to both sides)
y=26
Step: Substitute26 for y in x=−y+22:
x=−y+22
x=−26+22
x=−4(Simplify both sides of the equation)
3. x+y=45;x+2y=36
Step: Solve x+y=45 for x:
x+y+−y=45+−y(Add -y to both sides)
x=−y+45
Step: Substitute−y+45 for x in x+2y=36:
x+2y=36
−y+45+2y=36
y+45=36(Simplify both sides of the equation)
y+45+−45=36+−45(Add -45 to both sides)
y=−9
Step: Substitute−9 for y in x=−y+45:
x=−y+45
x=−(−9)+45
x=54(Simplify both sides of the equation)
I hope this helped!
Find the missing angles
Answers
Answer:
See explanation:
Step-by-step explanation:
1: 180-50=130
3: vertical angles are the same, therefore 50
4: 180-50=130
5: angle 1 equals angle 5, therefore 130
6: 50
7: 50, angles 6 and 7 are vertical therefore equal
8: 180-50=130
Please answer this! 100 Points!
Answers
Answer:
23ft!!
Step-by-step explanation:
brainliest please?
Answer:
23 ft
Step-by-step explanation:

HELP ASAP! I will mark Brainlist! Thanks (:
Answers
Answer:
Corresponding angles postulate
Answer:
definition of parrallel lines
Step-by-step explanation:
oh sorry. I understood it as parrallel
The owner of an apple orchard would like to estimate the mean number of usable apples produced per tree in his
large orchard. He selects a random sample of 10 trees from his large orchard. This dotplot displays the number of
usable apples produced for each of these trees.
Are the conditions for constructing at confidence interval met?
No, the random condition is not met.
No, the 10% condition is not met.
No, the Normal/large sample condition is not met.
Yes, the conditions for inference are met.
Answers
Step-by-step explanation:
know the normal large sample condition is not met and also there are outliers
Answer:
C
Step-by-step explanation:
No, the Normal/large sample condition is not met.
I need help
Please ?!!!!!!
Answers
Answer:
High blood pressure
Step-by-step explanation:
Possible DEATH
Answer:
High blood pressure
Step-by-step explanation:
High blood pressure is dangerous
Consider the line plot below.
What is the median of the data?
What is the mean?
Answers
which expression is equivalent to the expression -3(4x - 2) - 2x?
A- -8x
B- -16x
C- -14x -2
D- -14x + 6
Answers
Answer:
D is the answer
Step-by-step explanation:
You just distribute the negative three and combine like terms
Mr Baxter deposits 2,000 in an account that earns %5 simple interest how much is mr Baxter investment after 8 years?
Answers
Answer:
$2,800
Step-by-step explanation:
The formula for simple interest is I = PRT, where I is the interest (earned or paid), P is the principal amount invested/borrowed, R is the rate in decimal form, and T is the time in years.
I = (2000)(0.05)(8)
I = $800
Then we add that to the principal to get $2,800
---------------------------------
Joey made a deposit into an account that earns 6% simple interest. After 3 years, Joey earned $400. How much was Joey's initial deposit?
I = PRT
400 = P(0.06)(3)
400 = 0.18P
P = $2,222. 22
----------------------------------------
Peter is calculating the interest earned on a deposit of $275 in an account that earns 8% simple interest after 12 years. What is the ??? guessing interest earned?
I = PRT
I = (275)(0.08)(12)
I = $264
------------------------------------
Neil's grandmother has left him a small inheritance of $6,000. Neil would like to invest it at a rate of 5% interest. What is the simple???
I = PRT
I = (6000)(0.05)(T)
Please let me know if you have questions, or want to fill in the missing information on questions 3 & 4.
What happens to the volume of a sphere if its radius is multiplied by 6?
Answers
Answer:
216 times the original
Step-by-step explanation:
Volume 1 = 4/3 πr³
volume 2 = 4/3 π(6r)³
v 2 / v 1 = 6³ = 216
When the radius of a sphere is multiplied by 6, the volume is multiplied by 216
How to determine the volume?Let the radius of the sphere be r
The volume of a sphere of radius, r is calculated as:
v = 4/3 πr³
When multiplied by 6, the radius becomes:
R = 6r
The new volume is then calculated as:
V = 4/3 π(6r)³
Divide both volumes
V/v = 4/3 π(6r)³ / 4/3 πr³
Evaluate the quotient
V/v = 6³
V/v = 216
Hence, when the radius of a sphere is multiplied by 6, the volume is multiplied by 216
Read more about volumes at:
https://brainly.com/question/1972490
Which of the following scatterplots would have a trend line with a negative slope?
Answers
Answer:
Step-by-step explanation:
If we let the points in the first graph define the position and slope of a line through the points, this line would have a negative slope and a negative trend line. As x increases, y decreases.
Answer: it’s A. I took the test.
Step-by-step explanation:
the Beatles are better than the stones and that is a fact
Find the value of x in the triangle shown below 8 2
Answers
Answer:
8.25
Step-by-step explanation:
(8x 8) + (2x2) = x ^2
64 + 4 = x2
x = √68
x = 8.25
the product of 5 and 6 reduced by t
Answers
Answer:
5(6-t)
Step-by-step explanation:
in math, product means the "sum" of the equation or the final answer
and in your case, that means 5*6, but then we also have to remember that we're "reducing" or subtracting 't'-
5(6-t)
good luck :)
i hope this helps
brainliest would be highly appreciated
have a nice day!
Four pounds of bananas cost $6. What is the cost per pound of bananas?
Question 7 options:
$24 per pound
$1.50 per pound
$1 per pound
$6 per pound
Answers
Shannon is creating a scale drawing of her classroom. If she is using the scale 1/2 inch = 1 foot and the room model is 10 inches by 15 inches, what are the dimensions of the actual room. Please help me!
Answers
Answer:
30 foot by 20 foot
Step-by-step explanation:
1 inch = 10 inch
2 foot = d foot
Cross products: 1xd=2x10
d=20foot
1 inch = 15 inch
2 foot = d foot
Cross products: 1xd=2x15
d=30foot
A variable is normally distributed with mean 18 and standard deviation 8. Use your graphing calculator to find each of the following areas. Write your answers in decimal form. Round to the nearest thousandth as needed.
a) Find the area to the left of 18.
0
Incorrect
b) Find the area to the left of 14.
c) Find the area to the right of 17.
d) Find the area to the right of 19.
e) Find the area between 14 and 30.
Answers
Answer:
a) The area to the left of 18 is 0.5.
b) The area to the left of 14 is if 0.309.
c) The area to the right of 17 is of 0.55.
d) The area to the right of 19 is of 0.45.
e) The area between 14 and 30 is of 0.624.
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X, which is the area to the left of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X, which is the area to the right of X.
A variable is normally distributed with mean 18 and standard deviation 8
This means that [tex]\mu = 18, \sigma = 8[/tex]
a) Find the area to the left of 18.
This is the pvalue of Z when X = 18.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{18 - 18}{8}[/tex]
[tex]Z = 0[/tex]
[tex]Z = 0[/tex] has a pvalue of 0.5.
So the area to the left of 18 is 0.5.
b) Find the area to the left of 14.
This is the pvalue of Z when X = 14. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{14 - 18}{8}[/tex]
[tex]Z = -0.5[/tex]
[tex]Z = -0.5[/tex] has a pvalue of 0.309
The area to the left of 14 is if 0.309.
c) Find the area to the right of 17.
This is 1 subtracted by the pvaleu of Z when X = 17. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{17 - 18}{8}[/tex]
[tex]Z = -0.125[/tex]
[tex]Z = -0.125[/tex] has a pvalue of 0.45
1 - 0.45 = 0.55
The area to the right of 17 is of 0.55.
d) Find the area to the right of 19.
This is 1 subtracted by the pvaleu of Z when X = 19. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{19 - 18}{8}[/tex]
[tex]Z = 0.125[/tex]
[tex]Z = 0.125[/tex] has a pvalue of 0.55
1 - 0.55 = 0.45
The area to the right of 19 is of 0.45.
e) Find the area between 14 and 30.
This is the pvalue of Z when X = 30 subtracted by the pvalue of Z when X = 14.
X = 30
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{30 - 18}{8}[/tex]
[tex]Z = 1.5[/tex]
[tex]Z = 1.5[/tex] has a pvalue of 0.933
From b), when X = 14, Z has a pvalue of 0.309.
0.933 - 0.309 = 0.624
The area between 14 and 30 is of 0.624.
The area to the left of 18 is 0.5, the area to the left of 14 is 0.309, the area to the right of 17 is 0.55, the area to the right of 19 is 0.45, and the area between 14 and 30 is 0.624.
Given :
A variable is normally distributed with a mean of 18 and a standard deviation of 8.
a) Use the z score formula in order to determine the area to the left of 18.
[tex]\rm Z = \dfrac{X-\mu}{\sigma}[/tex]
[tex]\rm Z = \dfrac{18-18}{8}=0[/tex]
For the z = 0 the p-value is 0.5.
Therefore, 0.5 is the area to the left of 18.
b) Use the z score formula in order to determine the area to the left of 14.
[tex]\rm Z = \dfrac{X-\mu}{\sigma}[/tex]
[tex]\rm Z = \dfrac{14-18}{8}=-0.5[/tex]
For the z = -0.5 the p-value is 0.309.
Therefore, 0.309 is the area to the left of 14.
c) Use the z score formula in order to determine the area to the right of 17.
[tex]\rm Z = \dfrac{X-\mu}{\sigma}[/tex]
[tex]\rm Z = \dfrac{17-18}{8}=-0.125[/tex]
For the z = -0.125 the p-value is 0.45.
Therefore, the area to the left of 17 is given by:
= 1 - 0.45 = 0.55
d) Use the z score formula in order to determine the area to the right of 19.
[tex]\rm Z = \dfrac{X-\mu}{\sigma}[/tex]
[tex]\rm Z = \dfrac{19-18}{8}=0.125[/tex]
For the z = 0.125 the p-value is 0.55.
Therefore, the area to the left of 19 is given by:
= 1 - 0.55 = 0.45
e) Use the z score formula in order to determine the area between 14 and 30.
At X = 30 the z score becomes:
[tex]\rm Z = \dfrac{X-\mu}{\sigma}[/tex]
[tex]\rm Z = \dfrac{30-18}{8}=1.5[/tex]
For the z = 1.5 the p-value is 0.933.
For the z = -0.5 the p-value is 0.309.
Therefore, the area to the left of 14 is given by:
= 0.933 - 0.309
= 0.624
For more information, refer to the link given below:
https://brainly.com/question/13299273
There is a box of colored marbles on the counter top. There are 24 blue, 16 green, and 56 red.
Write the ratio of green marbles to red marbles. Don't forget to put your answer in simplest form.
Answers
Answer:
i think its 2:7
Step-by-step explanation:
heres why
16 and 56 both have a number that equals which it is 8
so u divide
16/8=2
56/8=7
16:56 in simplest form is 2:7
I need to solve for x. The interior angles are 30 and 4x+2. The exterior angle is 8+6x.
Answers
Answer:
x + y + z = 180 (this is the first equation)
w + z = 180 (this is the second equation)
Now, rewrite the second equation as z = 180 - w and substitute that for z in the first equation:
x + y + (180 - w) = 180
x + y - w = 0
x + y = w
Step-by-step explanation:
of 20 possible books you plan to take 5 with you on vacation. how many different collections of 5 books can you take?
Answers
What’s is the median number of guest at these parties
Answers
Answer:
21
Step-by-step explanation:
21 and 27
You are only given an option of 21, so take it.
Answer:
its 21
Step-by-step explanation:
A ______________ consists of an a sample space and a list of events with their probabilities.
probability model
sample space
likelihood
outcome
Answers
Sample space َََ َ َ َ َ َ َ َ َ َ
Mrs. Torchia picked 54 flowers, which represents 60% of all the flowers in her garden.How many flowers are left in Mrs. Torchia’s garden?
Answers
Alma is estimating the proportion of students in her school district who, in the past month, read at least 1 book. From a random sample of 50 students, she found that 32 students read at least 1 book last month. Assuming all conditions for inference are met, which of the following defines a 90 percent confidence interval for the proportion of all students in her district who read at least 1 book last month?
a. 32 + or - 1.645 underroot(32)(18)/50.
b. 32 + or - + 1.96 underroot(32)(18)/50.
c. 0.64 + or - 1.282 underroot(0.64)(0.36)/50.
d. 0.64 + or - 1.645 underroot(0.64)(0.36)/50.
e. 0.64 + or - 1.96 underroot(0.64)(0.36)/50.
Answers
Answer:
[tex]0.64 \pm 1.645\sqrt{\frac{0.64*0.36}{50}}[/tex], option D
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].
From a random sample of 50 students, she found that 32 students read at least 1 book last month.
This means that [tex]n = 50, \pi = \frac{32}{50} = 0.64[/tex]
90% confidence level
So [tex]\alpha = 0.1[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.1}{2} = 0.95[/tex], so [tex]Z = 1.645[/tex].
Confidence interval:
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
[tex]0.64 \pm 1.645\sqrt{\frac{0.64*0.36}{50}}[/tex]
So the correct answer is given by option D.
9.A standard IQ test produces normally distributed results with a mean of 100 and a standard deviation of 15. A class of high school science students is grouped homogeneously by excluding students with IQ scores in either the top 15% or the bottom 15%. Find the lowest and highest possible IQ scores of students remaining in the class.(7)
Answers
Answer:
The lowest possible IQ scores of students remaining in the class is 84.46.
The highest possible IQ scores of students remaining in the class is 115.54.
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Mean of 100 and a standard deviation of 15.
This means that [tex]\mu = 100, \sigma = 15[/tex]
Find the lowest and highest possible IQ scores of students remaining in the class.
Lowest:
The 15th percentile, which is X when Z has a pvalue of 0.15, so X when Z = -1.036.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]-1.036 = \frac{X - 100}{15}[/tex]
[tex]X - 100 = -1.036*15[/tex]
[tex]X = 84.46[/tex]
Highest:
The 100 - 15 = 85th percentile, which is X when Z has a pvalue of 0.85, so X when Z = 1.036.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]1.036 = \frac{X - 100}{15}[/tex]
[tex]X - 100 = 1.036*15[/tex]
[tex]X = 115.54[/tex]
The lowest possible IQ scores of students remaining in the class is 84.46.
The highest possible IQ scores of students remaining in the class is 115.54.
The product of 8 and the sum of a number and 12 is 240
Answers
Answer:
18
Step-by-step explanation:
Let the number be 'x'
Sum of 'x' and 12 = x +12
The product of 8 and the sum of a number and 12 = 8* (x +12)
= 8*x + 8*12
= 8x + 96
8x + 96 = 240
Subtract 96 from both sides
8x + 9 6 - 96 = 240 - 96
8x = 144
Divide both sides by 8
x = 144/8
x = 18