Question

1. If n=19, ¯xx¯(x-bar)=34, and s=12, construct a confidence interval at a 95% confidence level. Assume the data came from a normally distributed population.

Give your answers to one decimal place.

2. In a survey, 11 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $50 and standard deviation of $15. Construct a confidence interval at a 90% confidence level.

Give your answers to one decimal place.

3. If n=30, ¯xx¯(x-bar)=48, and s=9, find the margin of error at a 80% confidence level

Give your answer to two decimal places.

4. In a survey, 22 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 $7. Find the margin of error at a 98% confidence level.

Give your answer to two decimal places.

Answer 1