# Variable Nor95% CIStDev SE MeanMeanBuyItNow 9 630.78 20.47(615.04 646.52)6.82c. Interpret the 95 % confidence interval in context.d. Compared to the confidence interval (569, 599) forprices from auctions obtained in Example 6, is thereevidence that the mean price is higher when purchasedthrough Buy It Now? Explain.e. Excluding the observation of \$675, the confidence in-terval equals (615, 636). Does this change your answerto part d?Time spent on e-mail When the GSS askedn =people in 2012, "About how many hours per week doyou spend sending and answering e-mail?" (EMAILHR),the summary statistics were = 6.89 and s 13.05. TIoutput with these data (available on the book's website)is shown in the screen shot.10508.36afcta. What is the margin of error at the 95% confidence levelfor 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 de-viations below the mean, but the largest value of 168hours has a z-score larger than 12). Is this a concern forthe validity of the confidence interval?rn.m-NORMAL FIX3 AUTO REAL RADIAN CLa?TInterval(6.100.7.680)X-6.890Sx-13.050n=1050.00012Grandmas using e-mail For the question about e-mail inthe previous exercise, the 14 females in the GSS ofage at8.37

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Step 1

a)

The margin of error at the 95% confidence level is 0.79 and it is obtained below:

From the given information,

The lower limit is 6.100 and upper limit is 7.680.

Step 2

b)

Interpret the 95% confidence interval.

The 95% confidence interval is (6.100, 7.680).

There is a 95% cha...

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