Myers Business Systems is evaluating the introduction of a new product. The possible levels of unit sales and the probabilities of their occurrence are given next:

$\backslash$table$[[,$Sales in$,],[$Possible Market Reaction,Units,Probabilities$],[$Low response,$30,0\mathrm{.}30],[$Moderate response,$45,0\mathrm{.}20],[$High response,$55,0\mathrm{.}20],[$Very high response,$70,0\mathrm{.}30]]$

a$.$ What is the expected value of unit sales for the new product?

Note: Do not round intermediate calculations and round your answer to the nearest whole unit.

Expected value

units

b$.$ What is the standard deviation of unit sales?

Note: Do not round intermediate calculations. Round your answer to $2$ decimal places.