16 Laptop use in middle school. The American Secondary Education (Fall 2009) did a study of middle school students’

usage of laptop computers. For a sample of 106 students, the researchers reported the following statistics on how many minutes per day each student used a laptop for taking notes: x = 13.2, s = 19.5 . Now the researchers want to estimate the average amount of time per day laptops are used for taking notes for all middle school students across the country.

a. Define the target parameter for the researchers in words and symbols.

b. Calculate a 90% confidence interval for the target parameter. Interpret the result.

c. Explain what the phrase “90% confidence” implies in your answer to part c .