$5-70$ please $!!!$

$5-66.$ Two different types of injection$-$molding machines

are used to form plastic parts. A part is considered defective if

it has excessive shrinkage or is discolored. Two random sam$-$

ples, each of size $400,$ are selected, and $20$ defective parts are

found in the sample from machine $1$ whereas $10$ defective parts are found in the sample from machine $2.$Is it reasonable to conclude that both machines produce the same fraction of de$-$fective parts, using $\backslash$alpha $=0\mathrm{.}05?$ Find the P$-$value for this test.

$5-70.$ Construct a $95\%$ traditional CI on the difference in the

two fractions defective for Exercise $5-66.$