Answer:
The mean until the supplement is published is 140 months, while the standard deviation is of 11.8 months.
Step-by-step explanation:
The Poisson distribution is used to solve this question, as we have only the mean. In this distribution, the standard deviation is the square root of the mean.
In this question, we have that:
Species are discovered at a rate of once every 7 months.
A supplement to a guide is planned to be published after 20 new species have been discovered.
a) What are the expected value and standard deviation of the number of months (treated as a continuous measure of time) until the supplement is published?
Mean is: 7*20 = 140 months.
Standard deviation is [tex]\sqrt{140}[/tex] = 11.8 months.
The mean until the supplement is published is 140 months, while the standard deviation is of 11.8 months.
Suppose the population is all VCU students who track their steps each day. Among these students suppose the mean number of steps per day is 8989 with a standard deviation of 688. There are a few students who take many steps per day, and hence the distribution is skewed heavily to the right. If a simple random sample of 169 VCU students who track their steps each day is selected and the number of steps per day is determined for each, describe completely the sampling distribution of , the resulting mean number of steps per day for this sample of 169 VCU students who track their steps each day.
Answer:
By the Central Limit Theorem, the sampling distribution is approximately normal, with mean 8989 and standard deviation 52.92.
Step-by-step explanation:
Central Limit Theorem
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
Mean number of steps per day is 8989 with a standard deviation of 688.
This means that [tex]\mu = 8989, \sigma = 688[/tex]
Describe completely the sampling distribution of the resulting mean number of steps per day for this sample of 169 VCU students who track their steps each day.
Sample of 169 means that [tex]n = 169[/tex]
By the Central Limit Theorem, the sampling distribution is approximately normal, with mean [tex]\mu = 8989[/tex] and standard deviation [tex]s = \frac{688}{\sqrt{169}} = 52.92[/tex].
What percent of $40 is $35?
An initial investment of $3,000 earns 7% interest compounded continuously. What will the investment be worth in 19 years? (Round your answer to the nearest cent.)
Answer:
$11343.13
Step-by-step explanation:
From the given information:
Principal = 3000
rate = 7% = 0.07
time = 19 years.
The amount of investment after 19 years for a continuous compounded interest can be estimated by using the formula:
[tex]A = Pe^{rt} \\ \\ A = 3000 \times e^{0.07 \times 19} \\ \\ \mathbf{A = \$11343.13}[/tex]
Help this type of work confuses me
Answer/Step-by-step explanation:
Given:
-x + 3x + 1 + 4(x + 2) = 54
To solve, first open the bracket by applying the distributive property. Multiply every term you have in the bracket by 4
-x + 3x + 1 + 4x + 8 = 54
Add like terms together
6x + 9 = 54
Subtract 9 from each side
6x = 54 - 9
6x = 45
Divide both sides by 6
x = 45/6
x = 7.5
The ratio of boys to girls in the school
band is 4:3. If there are 16 boys, how
many boys and girls are in the band?
A. 12
B. 28
C. 7
D. 21
Answer:
B. 28
Step-by-step explanation:
Answer:
B. 28
Step-by-step explanation:
for every 4 boys there is 3 girls
so,
from 4 to 16 you multiply by 4,
4 x 4 = 16 (what you do to one you do to the other:
4 x 3 = 12
It's asking for the total amount
if there is 16 boys there is 12 girls with the ration of 16:12
add them up,
16 + 12 = 28 (That's your answer).
What is the measure of angle x? х 59: a. 120 b. II c. 121
Answer:
option (C) 121° is right answer
PLZ HELP PLZ HELP PLZ HELP WILL GIVE BRAINLY
Answer:
Steps 4 and 5
Step-by-step explanation:
Paula divided both sides in 4 and 5 to keep the equations equal.
Hope that this helps!
ACC Algebra 1 HW
Graphing inequalities has always been a subject that I've somewhat struggled on.
Answer:
y < x
Step-by-step explanation:
equation of line can be derived by finding slope and y-intercept
in this case the slope is 1 and the y-intercept is 0
equation is y = x
however, this is an inequality so answer is one of the following:
y > x or y < x
pick a point in the shaded region (these are the 'solutions'), let's pick (1, -1)
x = 1 and y = -1
which one is true? -1 > 1 or -1 < 1
-1 < 1 is the true one so inequality is y < x
Select the correct answer. Which statement is true about the y-intercept of a quadratic function? A. A quadratic function can only have one y-intercept. B. A quadratic function can have up to two y-intercepts. C. The y-intercept is also called a zero of the function. D. The y-intercept is located at the point where the value of y is 0.
Answer:
A. A quadratic function can only have one y-intercept.
Step-by-step explanation:
hope this helps. p.s. i really need brainliest :)
Answer:
A
Step-by-step explanation:
In the coordinate plane below, the xxx-axis represents the number of days after today, and the yyy-axis represents the temperature forecast in degrees Celsius. The points (3,7)(3,7)left parenthesis, 3, comma, 7, right parenthesis and (3,-3)(3,−3)left parenthesis, 3, comma, minus, 3, right parenthesis represent the high and low temperature forecasts of the same day.
Plot the points on the coordinate plane.
What is the difference between the high and the low temperature forecasts?
⬜ degrees Celsius
Answer:
10 degrees celsius
Step-by-step explanation:
Evan and Dorinda make bracelets for a craft fair.
Evan makes 10 bracelets the first day and 8 bracelets each day after that.
Dorinda makes 8 bracelets the first day and 8 bracelets each day after that.
If they make bracelets for 6 days, how many bracelets will they make in all?
Enter your answer in the box.
Answer:
98 bracelets are in the box
Answer:
112
Step-by-step explanation:
1 Femando exercised for twenty-five and
six-tenths minutes on Thursday. He exercised for
thirty and five-hundredths minutes on Friday. He
exercised eighteen and four-tenths minutes on
Saturday. How many total minutes did Fernando
exercise those three days?
A 74.5 C 73.85
B 73.15 D 74.05
Right the slope intercept form for the line that travels through (4,-1) and is parallel to y=1/4x
Answer:
Step-by-step explanation:
The slope is given to you by the line y = 1/4 x
The slope is just read as the number in front of x providing that the coefficient of y is 1. If that is not so, then you must divide by the coefficient in front of y. So far what you have is y = 1/4 x + b.
The second part of the question is to use the given point to find b.
x = 4
y = -1
b = ? substitute x and y to find b
y = 1/4 * 4 + b
- 1 = 1/4 * 4 + b
-1 = 1 + b
-2 = b
The equation of the line is y = 1/4 x - 2 Just to confirm this, I'm going to include the graph with the point 4,-1 on it.
In AHIJ, the measure of ZJ=90°, the measure of ZH=15°, and JH = 54 feet. Find the
length of HI to the nearest tenth of a foot.
Answer:
Step-by-step explanation:
Find the area of the polygon in square units.
Answer:
I wanna say 18 but I'm not to sure
This graph shows a linear relationship
between the water level in a tank and time
elapsed.
Enter the initial water level, in feet, of the
water tank.
What does the third equation become?
Answer:
8x-34=74
Explanation-
5th grade math. correct answer will be marked brainliest
Answer:
She got 9 multiple choice questions right.
She got 8 true/false questions right.
Step-by-step explanation:
you have to make them have a common denominator.
so multiply 4/5 by 2/2 and you get 8/10.
She got 9/10 multiple choice answers right and 8/10 true/false answers right.
Answer:
9 is the first one 8 is the second one
What is the next number in the arithmetic sequence below?
-32, -20, -8,4, _, ...
O A. 15
B. 18
O C. 12
D. 16
Answer:
D) 16
Step-by-step explanation:
it is going up by twelve each time.
so add twelve to 4 to get the answer.
Please help I’ll mark you as brainliest if correct!
Answer:
♥♥♥
I tried solving this answer and got 25.2. So, I think you're answer will be 25.
Step-by-step explanation:
I divided 63 by 2.5. Hope I helped.
Jane ran 72 miles in 6 days. Then she tripled her rate. How long would it take her to travel 648 miles at the new speed?
Plz help.
Answer:
18 days
Step-by-step explanation:
72/6=12 miles per day
12*3=36
648/36=18 days
please help.... 50% of my grade
Answer:
Ernesto's construction is wrong.
Step-by-step explanation:
Ernesto's construction is wrong.
This is because when bisecting an angle, the first thing we do is to place the compass at the vertex of the angle we want to bisect and draw an arc that will cross both lines that form the angle.
In Ernesto's case the arc drawn was not a single one but drawn separately as is seen in the image.
The arc on line AV does not continue to line VI but instead he drew another arc with different compass width on line VI before bisecting the angle.
The question is in the photo
Answer:
A or B.
A seems like best answer so far to me.
Step-by-step explanation:
Hope this helps!
A rectangular fish tank is 2m long, 1m wide and 1m deep. How many litres of water will it hold?
Answer:
2000 litres
Step-by-step explanation:
find the volume
v =2m×1m×1 m
= 2 m3
1m3 =1000litres
2m3=????
cross multiply
2m3 ×1000litres
1m3
Ans = 2000litres
Which of the following would NOT be a probability?
0.23
7
15/45
2/3
Answer:
7
Step-by-step explanation:
7 is a whole number and not a probability
True or False?
The domain and range of a cube root function are always all real numbers.
Answer:
True
For the cube root function f(x)=3√x f ( x ) = x 3 , the domain and range include all real numbers. Note that there is no problem taking a cube root, or any odd-integer root, of a negative number, and the resulting output is negative (it is an odd function).
Hope that helps!
Step-by-step explanation:
A company says its premium mixture of nuts contains % Brazil nuts, % cashews, % almonds, and % hazelnuts, and the rest are peanuts. You buy a large can and separate the various kinds of nuts. Upon weighing them, you find there are grams of Brazil nuts, grams of cashews, grams of almonds, grams of hazelnuts, and grams of peanuts. You wonder whether your mix is significantly different from what the company advertises.
1) Explain why the chi-square goodness-of-fit test is not an appropriate way to find out.
A) The chi-square goodness-of-fit test can only be used on counts, weights are quantitative, not counts.
B) The chi-square goodness-of-fit test can only be used on quantitative variable, weights are counts, not quantitative variables.
C) The expected values are percentages, and the actual values are not. Therefore the ch-square goodness-of-fit test cannot be used.
D) The chi-square goodness-of-fit test cannot be use to test this kind of claim
2) What might you do instead of weighing the nuts in order to use a X2 test?
A) There is no way of performing a test without using weight.
B) Count the number of each kind of nut, assuming the company's percentages are based on counts rather than weights.
C) Find the volume of each kind of nut, assuming the company's percentages are based on volume.
Answer:
A) The chi-square goodness-of-fit test can only be used on counts, weights are quantitative, not counts.
B) Count the number of each kind of nut, assuming the company's percentages are based on counts rather than weights.
Step-by-step explanation:
The Test of Goodnes for fit is based on the property that the χ² test is applicable when the cell probabilities depend on unknown parameters, provided that the unknown parameters are replaced with their estimates and provided that the one degree of freedom is deducted from each parameter estimated.
1) So if the estimates ( counts) are missing the test is not applicable.
2) Percentages if treated as counts can be used for the χ² test.
5. Laney is 4 feet 8 inches tall. There are 2.54
centimeters in 1 inch. What is Laney's height in
centimeters?
A. 22.05
B. 96.8
C. 142.24
O D. 160.32
will mark brainlest
Can someone help me?
9514 1404 393
Answer:
see below
Step-by-step explanation:
This is all about number sense: ordering and naming numbers. If you know your multiplication tables and a few key vocabulary words, that's all you need.
1a. perfect square
1b. irrational number
1c. greater than
__
2a. less than; greater than
2b. perfect square
2c. approximation
__
3a. square root
3b. square root
3c. approximation
3d. order; less than; less than
_____
When you fill in the blanks, the statements pretty much explain themselves.
__
Additional comment
For positive numbers, square and square root are operations that preserve order. That is, the square of a larger number is larger than the square of a smaller number. Likewise, the square root of a larger number is larger than the square root of a smaller number. Here, ...
81 > 64 > 44 ⇔ √81 > √64 > √44.
If a number is not a perfect square (a number multiplied by itself), then its square root is irrational.
In a math class with 19 students, a test was given the same day that an assignment was due. There were 10 students who passed the test and 11 students who completed the assignment. There were 6 students who failed the test and also did not complete the assignment. What is the probability that a student chosen randomly from the class passed the test and completed the homework?
Answer:
8/19
Step-by-step explanation:
The probability that a student is chosen randomly from the class passed the test and completed the homework will be 0.1637.
What is probability?Probability means possibility. It deals with the occurrence of a random event. The value of probability can only be from 0 to 1. Its basic meaning is something is likely to happen. It is the ratio of the favorable event to the total number of events.
In a math class with 19 students, a test was given the same day that an assignment was due.
There were 10 students who passed the test and 11 students who completed the assignment.
There were 6 students who failed the test and also did not complete the assignment.
Then the probability that a student is chosen randomly from the class passed the test and completed the homework will be
The number of the student who has done at least one assignment or passed the test is 19 - 6 = 13
n(A) = passes student
n(B) = given assignment
Then we have
[tex]\rm n(A \cap B) = n(A) + n(B) - n(A \cup B) \\\\n(A \cap B) = 10 + 11 - 13\\\\n(A \cap B) = 8[/tex]
Then the probability will be
[tex]\rm P = \dfrac{^8C_2}{^{19}C_2}\\\\P = \dfrac{28}{171}\\\\P = 0.1637[/tex]
More about the probability link is given below.
https://brainly.com/question/795909
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