Johnson Industries received a contract to develop and produce four high$-$intensity long$-$distance receiver$/$transmitters for cellular telephones. The first took $2,400$ labor hours and $$42,000$ worth of purchased and manufactured parts; the second took $2,060$ labor hours and $$40,320$ in parts; the third took $1,900$ labor hours and $$39,110$ in parts; and the fourth took $1,730$ labor hours and $$37,900$ in parts.

Johnson was asked to bid on a follow$-$on contract for another dozen receiver$/$transmitter units. $($Hint: There are two learning curvesone for labor and one for parts.$)$ Use Exhibit $6\mathrm{.}5.$

a$.$ How many labor hours should Johnson estimate are needed for the additional $12$ units? $($Round your answer to the nearest whole number.$)$

Estimated labor

hours

b$.$ How much should Johnson estimate the parts cost will be for the additional $12$ units? $($Round your answer to the nearest dollar amount.$)$

Estimated parts cost