Question # 04 A car manufacturer wants to estimate the mean fuel efficiency (in miles per gallon) of a new electric car model they have developed. They wish to develop a 90 percent confidence interval estimate with a margin of error of pm 2 miles per gallon. They select a pilot sample of n = 100 cars and find that the sample standard deviation is 4 miles per gallon. Find the net required sample size
Added by Soledad P.
Step 1
To find the z-score corresponding to a 90% confidence interval, we need to look at the standard normal distribution table or use a calculator. The area under the curve between the mean and the critical value is 0.45 (since 90% is split into 50% on either side of Show more…
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