18 You were interested in how long the average psychology ma

18. You were interested in how long the average psychology major at your college studies per night, so you asked 10 psychology majors to tell you the amount they study. They told you the following times: 2, 1.5, 3, 2, 3.5, 1, 0.5, 3, 2, 4. (a) Find the 95% confidence interval on the population mean. (b) Find the 90% confidence interval on the population mean. 100. What is meant by the term \'\'90% confident\'\' when constructing a confidence interval for a mean? a. If we took repeated samples, approximately 90% of the samples would produce the same confidence interval. b. If we took repeated samples, approximately 90% of the confidence intervals calculated from those samples would contain the sample mean. C. If we took repeated samples, approximately 90% of the confidence intervals calculated from those samples would contain the true value of the population mean. d. If we took repeated samples, the sample mean would equal the population mean in approximately 90% of the samples.

Solution

18)

Mean and varaince of the data would be 2.25 and 1.1125

a) 2.25 -1.96*1.054751/_/10 and 2.25+1.96*1.054751/_/10 => (1.596258 2.903742)

b) 2.25 -1.645*1.054751/_/10 and 2.25+1.645*1.054751/_/10 => (1.701324 2.798676)

100) C