math作业代写

## Due Date: March 22, 2019

math作业代写 Test for a significant difference at the 1% significance level and state whether you reject or fail to reject the null (and why).

### Assignment #3  math作业代写

Notes:

• All questions must be solved by hand (including charts/figures). Show your work for full credit.
• A hardcopy is due at the START of class. Indicate name, student ID and course number.
• Assignments have to be done independently.
• Late assignments will not be accepted.

1.) Apple is concerned that their market shares among women is different than that among men. Independent random samples of (men) and (women) were randomly selected from binomial populations 1 and 2 of cell phone purchasers in 2018, respectively. Sample 1 had 80 iPhones purchased, and sample 2 had 88 iPhones purchased.

1a. Suppose you wish to detect a difference between the two parameters if one exists. What should you choose as the null and alternative hypotheses for a statistical test?(1 point)  math作业代写

1b. Calculate the standard error of the difference in the two sample proportions  (1 point)

1c. Based on your knowledge of the standard normal distribution, is the standard error that you calculated previously (1b), a likely or an unlikely observation, assuming that  is true and the two population proportions are the same? Justify your conclusion.(2 points)

1d. Find the p-value for the test. Test for a significant difference at the 1% significance level and state whether you reject or fail to reject the null (and why).(2 points)

### 2.) Suppose the population standard deviation equals 10. What is the sample size needed to estimate, with 95% confidence, a population mean within 1.5 units of its true value?(2 points)  math作业代写

1. A comparison between the average completion time of a graduate school program in Fine Arts vs. Communications yielded the following results (in years), respectively: = 80, = 3.2, = 0.6, = 90, = 2.8, and = 0.7. Estimate , the difference in mean years of program completion. Based on a 95% confidence interval, is program completion time different between the two programs? Justify your answer.  (4 points)
2. A business owner wants to test whether the total wait time at his two restaurants (‘Pizza for everyone’, and ‘Burger Haven’) are similar with one another. A random sample of eight customers’ wait times was monitored from the two restaurants.

The data below reflect the time in minutes. Suppose  denotes the mean wait time for restaurant 1 and  denotes the mean wait time for restaurant 2. Assume both population distributions are normal.

 Pizza for everyone 5.2 4.3 6.7 7.8 3.9 5 6.3 4.7 Burger Haven 7.1 8.3 4.7 3.9 4.6 5.4 6 6.3

4a. Calculate whether the variances are equal with α=0.05. State what the null and alternative hypothesis are.(3 points)

4b. Regardless of what you concluded for 4a, test whether there is a significant difference between the two restaurants’ wait times. Use a 95% confidence interval. (4 points)   math作业代写

### 5.A tutor guarantees to his customers that his studying/learning tips will significantly improve their test scores. Exam scores (before and after) for five customers are provided below.

 1 2 3 4 5 Before 50 47.5 52.5 49 53 After 51 48 52.5 49.5 53.3

5a. State the appropriate null and alternative hypotheses to test whether the tutoring significantly improves test scores.(1 point)

5b. Calculate the value of the test statistic. (3 points)

5c. Based on an alpha of 0.05, determine whether you reject or fail to reject the null hypothesis. Justify your answer.(2 points)