8.36 Time spent on e-mail When the GSS asked n = 1050 people in 2012, “About how many hours per week do you spend sending and answering e-mail?” (EMAILHR), the summary statistics were x = 6.89 and s = 13.05. TI output with these data (available on the book’s website)

is shown in the screen shot.

a. What is the margin of error at the 95% confidence level for the point estimate of the mean number of hours?

b. Interpret the 95% confidence interval shown in context.

c. The distribution of hours spent is right-skewed (e.g., the minimum of zero hours is only 0.5 standard deviations below the mean, but the largest value of 168 hours has a z-score larger than 12). Is this a concern for the validity of the confidence interval?

Transcribed Image Text:

NORMAL FIX3 AUTO REAL RADIAN CL TInterval (6.100,7.680) x=6.890 Sx=13.050 n=1050.000 0