salary is desired.

a$.$ What is the planning value for the population standard deviation?

$=$

b$.$ How large a sample should be taken if the desired margin of error is $$300?$ Use a rounded $z$ value $(2$ decimals$)$ in your calculations. Round your answer for $n$ to next whole number.

$$190?$

$$100?$

c$.$ Would you recommend trying to obtain the $$100$ margin of error? Explain.