Jennifer wants to find a 95% confidence interval for the time it takes her to get to work.
She kept records for 30 days and found her average time to commute to work was 20.5
minutes with a standard deviation for the population of 3.9 minutes. Jennifer's margin of
error would be 1.4 minutes.

Question

Quizplus · Accepted Answer

Jennifer's margin of error cannot be directly determined without specifying the confidence level's corresponding z-score or t-score and without clarifying whether the standard deviation given is for the sample or the population. Since the question mentions a "standard deviation for the population," a z-score would typically be used for calculating the margin of error in a normal distribution. However, the actual margin of error calculation also depends on the sample size and the specified confidence level, which requires using the z-score for a 95% confidence interval.

Jennifer Wants to Find a 95% Confidence Interval for the Time