7. Sampling Distributions & Confidence Intervals: Mean

A puzzle company is interested in the average number of pieces in their jigsaw puzzles, so they plan to create a confidence interval for the true mean. The easiest puzzle in their line is $100$ pieces, and the largest is $1000$ pieces. Use the range rule of thumb to estimate the sample standard deviation.

A technology retailer is interested in the average price of their products, so they plan to create a $99\%$ confidence interval for the true mean. Find the minimum sample size needed so the margin of error is no more than $\mathrm{\backslash (}100$ if...

(A) The standard deviation is known to be about $\mathrm{\backslash )}324$

A technology retailer is interested in the average price of their products, so they plan to create a $99\%$ confidence interval for the true mean. Find the minimum sample size needed so the margin of error is no more than $\mathrm{\backslash (}100$ if...

(B) The standard deviation is unknown but the cheapest product is $\mathrm{\backslash )}198$ and the most expensive is $\$1500$.