A variable of a population has mean and standard deviation . For a large sample size n, fill in the blanks. Justify your answers.

A variable of a population has mean μ and standard deviation σ. For a large sample size n, fill in the blanks. Justify your answers.
a. Approximately ______________% of all possible samples have means within σ/√n of the population mean, μ.
b. Approximately ______________ % of all possible samples have means within 2σ/√n of the population mean, μ.
c. Approximately ______________ % of all possible samples have means within 3σ/√n of the population mean, μ.
d. Approximately ______________% of all possible samples have means within zα/2 of the population mean, μ