Question

In a survey, 16 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $37 and standard deviation of $17. Construct a confidence interval at a 95% confidence level.

Answer 1

CI= [28.67,45.33]

Explanation:

-Given the mean is $37 and the standard deviation is $17

#A 95% confidence interval can be calculated as follows:

`CI=\mu\pm z (\sigma)/(√(n))\\\\=\mu\pm z_(0.025)(\sigma)/(√(n))\\\\=37\pm1.96*(17)/(√(16))\\\\\\=37\pm8.33\\\\=[28.67,\ 45.33]`

Hence, the 95% confidence interval is [28.67,45.33]