Question

In a survey, 27 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $36 and standard deviation of $4. Find the margin of error at a 90% confidence level.

Answer 1

AI-generated answer

To find the margin of error at a 90% confidence level, we need to use the formula:

Margin of Error = Critical Value * Standard Deviation

1. Determine the critical value:

- Since we want a 90% confidence level, we need to find the z-score associated with this confidence level. The z-score for a 90% confidence level is approximately 1.645.

2. Calculate the margin of error:

- Given the standard deviation of $4, we can now calculate the margin of error using the formula:

Margin of Error = 1.645 * $4

Therefore, the margin of error at a 90% confidence level is approximately $6.58.

Please note that this calculation assumes the data follows a normal distribution and that the sample is representative of the population.

Explanation: