Question

In a survey, 61 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $39 and standard deviation of $3. Find the margin of error for a 99% confidence level.

Answer 1

0.989

Explanation:

The formula for Margin of Error is:

z × Standard deviation/√n

Where

z = z score for 99% confidence Interval

= 2.576

n = 61 people

Standard deviation = $3

Hence,

Margin of Error

= 2.576 × 3/√61

= 0.989