Mathematics, 28.12.2019 01:31 kim643

According to one investigator’s model, the data are like 400 draws made at random from a large box. the null hypothesis says that the average of the box equals 50; the alternative says that the average of the box is more than 50. in fact, the data averaged out to 52.75, and the sd was 25. compute z and p . what do you conclude?

Answers: 3

Show answers

Answers

Answer from: isadorahelena1

$z=\frac{52.75-50}{\frac{25}{\sqrt{400}}}=2.2$

p_v =2*P(Z2.2)=0.0278

If we compare the p value and the significance level assumed $\alpha=0.01$ we see that $p_v\alpha$ so we can conclude that we have enough evidence to fail reject the null hypothesis, so we can't conclude that the mean is significantly diffrent fro 50 at 1% of signficance.

Step-by-step explanation:

1) Data given and notation

$\bar X=52.75$ represent the mean height for the sample

s=25 represent the sample standard deviation

n=400 sample size

$\mu_o =50$ represent the value that we want to test

$\alpha$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

p_v represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean is equal to 50 or not, the system of hypothesis would be:

Null hypothesis: $\mu = 50$

Alternative hypothesis: $\mu \neq 50$

If we analyze the size for the sample is > 30 but we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value but we can assume it as z distribution, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$z=\frac{52.75-50}{\frac{25}{\sqrt{400}}}=2.2$

P-value

Since is a two sided test the p value would be:

p_v =2*P(Z2.2)=0.0278

Conclusion

Answer from: Quest

im sorry but no. i just need to answer for 50 poonts oof

Can anyone me with the algebra 1 a semester exam?

Answer from: Quest

you cant answer this dummy

step-by-step explanation:

Another question on Mathematics

Mathematics, 21.06.2019 15:00

Which of the greatest common gcf of 32 and 48 a 16 b 96 c 8 d 32

Answers: 2

Answer

Mathematics, 21.06.2019 18:00

Someone this asap for a group of students attends a basketball game. * the group buys x hot dogs at the concession stand for $2 each. * the group buys y drinks at the concession stand for $3 each. the group buys 29 items at the concession stand for a total of $70. how many hot dogs did the group buy?

Answers: 1

Answer

Mathematics, 21.06.2019 21:40

The point a is at –2 and the point b is at 7. marissa would like to divide this line segment in a 4: 3 ratio, and she would like to use the formula x = (x2 – x1) + x1. what values should she substitute into the formula? a = a + b = x1 = x2 =

Answers: 2

Answer

Mathematics, 22.06.2019 02:00

There are a total of 75 students in the robotics club and science club. the science club has 9 more students than the robotics club. how many students are in the science club?

Answers: 1

Answer

You know the right answer?

According to one investigator’s model, the data are like 400 draws made at random from a large box....

Questions