Statistics Homework

Question

In a survey, 25 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $44 and standard deviation of $17. Construct a confidence interval at a 98% confidence level.

Give your answers to one decimal place.

Answer 1

MOE=zxsd/sqrn = 2.326x 17/5, (z=2.326 for 98%, sd=17, n=25)

= about 7.91

CI = 44+/- 7.91

= about ($36.1, $51.9)