# Question: Many middle schools have initiated a program that provides every

Many middle schools have initiated a program that provides every student with a free laptop (notebook) computer. Student usage of laptops at a middle school that participates in the initiative was investigated in American Secondary Education (Fall 2009). In a sample of 106 students, the researchers reported the following statistics on how many minutes per day each student used his or her laptop for taking notes:

x = 13.2, s = 19.5

a. Compute the interval, x-bar ±2s.

b. Explain why the distribution of laptop usage for taking notes for these 106 students cannot be symmetric.

c. Given your answer to part b, what percentage of the 106 students have laptop usages that fall within the x-bar ± 2s interval?

x = 13.2, s = 19.5

a. Compute the interval, x-bar ±2s.

b. Explain why the distribution of laptop usage for taking notes for these 106 students cannot be symmetric.

c. Given your answer to part b, what percentage of the 106 students have laptop usages that fall within the x-bar ± 2s interval?

## Answer to relevant Questions

Refer to the Evolutionary Ecology Research (July 2003) study of the patterns of extinction in the New Zealand bird population, presented in Exercise 2.20 (p. 37). Consider the data on the egg length (measured in millimeters) ...Compare the z -scores to decide which of the following x values lie the greatest distance above the mean and the retest distance below the mean: a. x = 100, µ = 50, σ = 25 b. x = 1, µ = 4, σ = 1 c. x = 0, µ = 200, σ ...With mound-shaped data, what proportion of the measurements have z-scores between –3 and 3? A city librarian claims that books have been checked out an average of seven (or more) times in the last year. You suspect he has exaggerated the checkout rate (book usage) and that the mean number of checkouts per book per ...For each of the data sets in parts a–d, compute x-bar, s2, and s. a. 13, 1, 10, 3, 3 b. 13, 6, 6, 0 c. 1, 0, 1, 10, 11, 11, 15 d. 3, 3, 3, 3 e. For each of the data sets in parts a–d, form the interval x-bar ± ...Post your question