30,000 per year. To test her hypothesis, she has collected a simple random sample of 100 starting clerical salaries from across the state and found that the sample mean is $29,750. a. State the appropriate null and alternative hypotheses. b. Assuming the population stand

1. The National Center for Educational Statistics recently chose a random sample of 100 newly graduated college students and queried each one about the time it took to complete his or her degree. If the sample mean was 5 years with a sample variance of 4 years: a. Construct a 95 percent confidence interval estimate of the mean completion time of all newly graduated students. b. а. b. What is the interpretation of this confidence interval? If the sample increases, what will happen to the width of the confidence band (explain why you believe so). From past history, the average time for students to complete the degree is 4.8 years. Test the hypothesis at the level of 0.05 that it takes longer for students to complete the degree now. с.

The average starting salary of students who graduated from colleges of Business in 2009 was $48,800. A sample of 100 graduates of 2010 showed an average starting salary of $50,000. Assume the standard deviation of the population is known to be $7000. We want to determine whether or not there has been a significant increase in the starting salaries. a. State the null and alternative hypotheses to be tested. b. Compute the test statistic. c. The null hypothesis is to be tested at the 5% level of significance. Determine the critical value for this test. d. What do you conclude from the test? e. What does the test result mean in the context of this problem?

1. According to the records of an auto insurance company, the average distance that their customers drive to work is 17.4 miles. You are a new agent, and you think this is too low. You do a random polling of 50 of the company's customers, and you find that the average is 18.5 miles with a standard deviation of 3.4 miles. Do these data provide enough evidence at the 0.05 level of significance to conclude that the average distance driven to work is actually more than 17.4 miles? A. State the null and alternative hypotheses B. State the p-value. C. What is your conclusion about the null hypothesis? D. What is your conclusion in context of this problem?

In a particular year, registered nurses earned an average annual salary of $52,330. A survey was conducted with 48 nurses from a particular state to determine if the annual salary is higher than $52,330 for that state's nurses. The sample average was $61,599 with a sample standard deviation of $7,489. Conduct a hypothesis test at the 5% level.Note: If you are using a Student's t-distribution for the problem, you may assume that the underlying population is normally distributed. (In general, you must first prove that assumption, though.) State the distribution to use for the test. (Enter your answer in the form z or tdf where df is the degrees of freedom.) What is the test statistic? (Round your answer to two decimal places.) What is the p-value? (Round your answer to four decimal places.) Construct a 95% confidence interval for the true mean. Sketch the graph of the situation. Label the point estimate and the lower and upper bounds of the confidence interval. (Round your answers to the…

MC Qu. 10-64 Sales at a fast-food restaurant average... Sales at a fast-food restaurant average $6,000 per day. The restaurant decided to introduce an advertising campaign to Increase daily sales. In order to determine the effectiveness of the advertising campaign, a sample of 49 day's sales were taken. The sample showed average daily sales of $6,300. From past history, the restaurant knew that its population standard deviation is about $1,000. If the level of significance is 0.01, have sales increased as a result of the advertising campaign? Multiple Choice Fail to reject the null hypothesis. Reject the null hypothesis and conclude the mean is higher than $6,000 per day. Reject the null hypothesis and conclude the mean is lower than $6,000 per day. Reject the null hypothesis and conclude that mean equal to $6,000 per day.

c) State your conclusion in a complete sentence: 3) A college wants to see if there is a significant difference in the amount of time an average full- time student studies each week compared to the national average of 17 hours. Given that a random sample of 140 students studied an average of 15.5 hours with a population standard deviation of 6.4 hours, determine if there is a significant difference between this college and the national average. Test at a 95% confidence level. (a < 0.05) Ho: μ = 17 The null and alternative hypotheses: a) Compute the test statistic (z-score): b) What is the p-value for the test statistic? c) State your conclusion in a complete sentence: HA: μ # 17

1. Suppose a random sample of 32 National Football League players had an average weight of 252.5 pounds. Assume that the standard deviation for weight of all players in the league is 31 pounds. Determine the margin of error for a 99% confidence interval for this sample.