How much do you typically pay, including tips, for a haircut? In a survey of 50 students in her class, one of the authors found the average amount paid for haircuts to be $45.68 and the standard deviation to be $39.95. Th e data are not strongly skewed.
a. Explain how you know from the sample average and sample standard deviation that the distribution of price of haircuts is not bell-shaped.
b. In the context of this study, explain why it is valid to use the theory-based (t-distribution) approach to find a confidence interval?
c. Use the Theory-Based Inference applet to find and report a 95% confidence interval for the parameter of interest. Also, interpret the interval in the context of the study.