Standard Error of the Mean vs. Standard Deviation

When we move from the basic normal distributionto the samplingdistribution of the meanwe substitute the standard errorof the mean for the standard deviationwhen we make the conversion to the standardized normal distribution. Why do we use the standard error of the mean in this case? And how does using the standard error affect our confidence intervalscalculations? (Hint – these two issues are related).

The solution determines the standard error of the mean versus standard deviation.