Question

In a survey, 14 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $34 and standard deviation of $4. Find the margin of error at a 90% confidence level. Give your answer to two decimal places.

Answer 1

The margin of error is 1.76

Step-by-step explanation:

The formula for calculating:

ME= z*
`(σ)/(√(n) )`

Where:

z= 90%= The level of confidence of the results (also called interval or degree of confidence, generally set at 95% in the survey industry).In this case, it is 1.65

n= sample= 14

σ= standard deviation of $4.

ME= z*
`(σ)/(√(n) )`

ME= 1.65*
`(4)/(√(14) )`

ME=1.65* 1.069

ME=1.76