1) The mean annual tuition and fees for a sample of 16 private colleges was $37000 with a standard deviation of $5000. A dotplot shows that it is reasonable to assume that the population is approximately normal. You wish to test whether the mean tuition and fees for private colleges is different from $33500. Compute the value of the test statistic. 2)A carpet company advertises that it will deliver your carpet within 6 days of purchase. A sample of 46 past customers is taken. The average delivery time in the sample was 6.8 days. The sample standard deviation is 2.7 days. Assume that the delivery time is normally distributed. Test to determine if their advertisement is legitimate at a confidence level 0.05. (Show all steps) 3) A random sample of 18 light bulbs is drawn from a normally distributed population. The sample mean and standard deviation are 517 hours and 39 hours, respectively. Provide the upper confidence limit for a 90% confidence interval for the mean life, μ, of all light bulbs of this type. Round you answer to the nearest integer. 4) In 1995, the mean duration of long-distance telephone calls originating in one town was 6.5 minutes. A long-distance telephone company wants to perform a hypothesis test to determine whether the mean duration of long-distance phone calls has changed from 1995. Determine the null and alternative hypotheses. 5) A study of 25 professors showed that the average time they spent creating test questions was 16.5 minutes per question. The standard deviation of the population is 5. Which of the following is the 99% confidence interval for the average number of minutes it takes to create a test question? Assume that the population is normally distributed. 6) A sample of 50 chewable vitamin tablets have a sample mean of 230 milligrams of vitamin C. Nutritionists want to perform a hypothesis test to determine how strong the evidence is that the mean mass of vitamin C per tablet exceeds 225 milligrams. State the appropriate null and alternative hypotheses. 7) Find the confidence level related to the critical value zα/2=2.16 8) Three years ago, the average starting salary of a new business graduate with a major in accounting in UAE was 15,000 Dhs. A random sample of 10 accounting graduates from this year's graduating class of ZU is selected. The ZU management wants to determine if the starting salaries have increased in the last three years. Assume that the population of starting salaries in accounting is strongly skewed. Which one of the following tests is appropriate for this problem?
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2)A carpet company advertises that it will deliver your carpet within 6 days of purchase. A sample of 46 past customers is taken. The average delivery time in the sample was 6.8 days. The sample standard deviation is 2.7 days. Assume that the delivery time is
Test to determine if their advertisement is legitimate at a confidence level 0.05. (Show all steps)
3) A random sample of 18 light bulbs is drawn from a normally distributed population. The sample mean and standard deviation are 517 hours and 39 hours, respectively. Provide the upper confidence limit for a 90% confidence interval for the mean life, μ, of all light bulbs of this type. Round you answer to the nearest integer.
4) In 1995, the mean duration of long-distance telephone calls originating in one town was 6.5 minutes. A long-distance telephone company wants to perform a hypothesis test to determine whether the mean duration of long-distance phone calls has changed from 1995. Determine the null and alternative hypotheses.
5) A study of 25 professors showed that the average time they spent creating test questions was 16.5 minutes per question. The standard deviation of the population is 5. Which of the following is the 99% confidence interval for the average number of minutes it takes to create a test question? Assume that the population is normally distributed.
6) A sample of 50 chewable vitamin tablets have a sample mean of 230 milligrams of vitamin C. Nutritionists want to perform a hypothesis test to determine how strong the evidence is that the mean mass of vitamin C per tablet exceeds 225 milligrams. State the appropriate null and alternative hypotheses.
7) Find the confidence level related to the critical value zα/2=2.16
8) Three years ago, the average starting salary of a new business graduate with a major in accounting in UAE was 15,000 Dhs. A random sample of 10 accounting graduates from this year's graduating class of ZU is selected. The ZU management wants to determine if the starting salaries have increased in the last three years. Assume that the population of starting salaries in accounting is strongly skewed. Which one of the following tests is appropriate for this problem?
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