Question 10 of 13 - Quiz 384.6%ResourcesFeedbackResumeAttempt 1The gestation time of humans has an approximate Normal distribution with a mean of 250 days and a standard deviation of 6.0 days. A simple random sample of n newborns is to be taken.What is the minimum sample sized needed so that the sampling distribution of xˉ has a standard deviation of 0.5 day?1441225015incorrect
Q. Question 10 of 13 - Quiz 384.6%ResourcesFeedbackResumeAttempt 1The gestation time of humans has an approximate Normal distribution with a mean of 250 days and a standard deviation of 6.0 days. A simple random sample of n newborns is to be taken.What is the minimum sample sized needed so that the sampling distribution of xˉ has a standard deviation of 0.5 day?1441225015incorrect
Use formula for standard deviation: Use the formula for the standard deviation of the sampling distribution of the sample mean, which is σ/n, where σ is the population standard deviation and n is the sample size.
Set up equation: We want the standard deviation of the sample mean to be 0.5 days. The population standard deviation is 6.0 days. So, set up the equation n6.0=0.5.
Square both sides: Square both sides of the equation to solve for n. (6.0/0.5)2=n.
Calculate value of n: Calculate the value of n. (6.0/0.5)2=(12)2=144.
More problems from Interpret measures of center and variability