In a survey, 41 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $30 and standard deviation of $2. Construct a confidence...

In a survey, 41 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $30 and standard deviation of $2.

Construct a confidence interval in the form estimate ± margin of error at a 90% confidence level.