Question: A research firm surveyed 64 randomly selected Americans to determine the mean amount spent on coffee during 1 week. The sample mean was $20 per week. The population distribution was normal with a standard deviation of $5. What is the 95% confidence interval for population mean?
Added by Elizabeth P.
Step 1
The standard error is calculated by dividing the standard deviation by the square root of the sample size. In this case, the standard deviation is $5 and the sample size is 64. So, the standard error is $5/√64 = $0.625. Show more…
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