According to a food and drug administration (fda) study, a cup of coffee contains an average of 115 mg of caffeine, with the amount per cup ranging from 60-180 mg. suppose u want to repeat the fda experiment in order to obtain an estimate of the mean caffeine content in a cup of coffee correct to withing 5 mg with 95% confidence. how many cups of coffee would have be included in your sample?

139

Step-by-step explanation:

As per given , we have

The amount of caffeine per cup is ranging from 60-180 mg.

Range = Maximum - Minimum = 180 -60 =12

According to Range -rule ,

Standard deviation =

Formula for sample size : , where z* is critical z value and E is margin of error.

By z-table , the critical z-value for 95% confidence interval = 1.96

E= 5

Put all values in formula , we get

Hence, 139 cups of coffee would have be included in the sample.

answer: i believe c. is the answer sorry if i am wrong

step-by-step explanation: