Question: What formula is used to gain information about a sample mean when the variable is normally distributed or when the sample size is 30 or more?
A ) z = X-μσ B ) z = X‾-μσn C ) z = X‾-μσn D ) z = X-μσ
Steps to derive
1z = X-μσ is used to gain information about an individual data value when the variable is normally distributed.
2z = X‾-μσn is used to gain information when applying the central limit theorem about a sample mean when the variable is normally distributed or when the sample size is 30 or more.
