Question

1. According to a 2011 report by the U.S. Department of Labor, civilian Americans spend 2.75 hours per day watching television. A faculty researcher, Dr. Sameer, at California Polytechnic State University (Cal Poly) conducts a study to see whether a different average applies to Cal Poly students. He surveys a random sample of 100 Cal Poly students and finds the mean number of hours spent watching TV is 3.07 hours. The sample standard deviation is 1 hour. The sample distribution is not strongly skewed.

a. Describe the parameter in words. Assign a symbol to it.

b. What is the value for the statistic? Assign a symbol to it.

c. Describe the null hypothesis in words.

d. Describe the alternative hypothesis in words.

e. Write your null hypothesis and alternative hypothesis from part c and d using symbols.

f. Why we can use theory-based approach for this study?

g. Calculate the t-statistic. Show your work. h. Based on your t-statistic, do you have strong evidence against the null hypothesis?

i. Based on your result from part h, what type of error may occur?

j. Describe the type of error you identify in part I in the context of the question.

Answer 1

a) Parameter - average time spent per day watching television

b) Statistic - mean number of hours spent watching TV in a random sample of 100 Cal Poly students

Let denotes the true mean number of hours spent watching TV.

i) Since we rejected H₀ , in this case type I occur may occur that means reject H₀ though H₀ is actually true.

j) Type I error