Hypothesis Testing: Two sample z test & Effect of Skewness

Each response must include your calculations.
This problem requires you to complete all steps for the hypothesis testing process.
A cell phone company offers two plans to it subscribers. At the time new subscribers sign up, they are asked to provide some demographic information. The mean yearly income for a sample of 40 subscribers to Plan A is $57,000 with a standard deviation of $9,200. This distribution is positively skewed; the actual coefficient of skewness is 2.11. For a sample of 30 subscribers to Plan B the mean income is $61,000 with a standard deviation of $7,100. The distribution of Plan B subscribers is also positively skewed, but not as severely. The coefficient of skewness is 1.54.

Complete the following:

a. At the .05 significance level, is it reasonable to conclude the mean income of those selecting Plan B is larger?

b. What is the p-value? Report the p-value to 4 decimal places.

c. Do the coefficients of skewness affect the results of the hypothesis test? Why?

Solution Summary

The solution provides step by step method for the calculation of testing of hypothesis. The solution also explains how the coefficient of skewness affects hypothesis testing. Formula for the calculation and Interpretations of the results are also included. Interactive excel sheet is included. The user can edit the inputs and obtain the complete results for a new set of data.

Please see the attached file.
A hypothesistest is used to test a claim. You get 1.75 as your test statistic and 1.59 as your critical value for a right-tailed test. Which of the following is the correct decision statement for the test?
A. Reject the null hypothesis
B. Claim the null hypothesis i

A pharmaceutical manufacturer is concerned that the mean impurity concentration in pills should not excess 2%. It is known that impurity concentrations follow a normal distribution with a population standard deviation 0.32%. A random sample of 64 pills from a production run was checked, and the sample mean impurity concentration

Find effect of a treatment using a two tailed test
Givens: A sample of n = 9 that receives the treatment, a population mean m = 40, a standard deviation s = 9, and an after treatment sample mean of M = 33.
Is the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with alpha = .

Question: Determine the p-value for each of the following hypothesis-testing situations:
a. H0: p = 0.25 and Ha: p does not = 0.25; z test value = 1.84
b. H0: u >/= 13.5 and Ha: u < 13.5; t test value = -1.94 d.f. = 10

A sample of 64 observations is selected from a normal population. The sample mean is 215, and the sample standard deviation is 15. Conduct the following test of hypothesis using the .03 significance level.
H0: µ ≥ 220
H1: µ < 220
(a) Is this a one- or two-tailed test?
(b) What is the decision rule?
(c) What is

Givens: A sample of n = 9 that receives the treatment, a population mean m = 40, a standard deviation s = 9, and an after treatment sample mean of M = 33.
Is the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with alpha = .05, and later, if the standard deviation is changed to

A two tailed hypothesistest is being uses to evaluate a treatment effect with o= .05. if the sample data produce a z- score of z= -2.24 what is the correct decision?
* reject the null hypothesis and conclude that the treatment has an effect
* fail to reject the null hypothesis and conclude that the treatment has no effect