<span>a.
</span>Do you
have sufficient funds to estimate the population mean for the attribute of
interest with a 95% confidence interval 4 units width? Assume that sd= 12
n= {[(Zalpha/2)^2]*[sd]^2}/
se^2
n=
(1.96)^2*(12)^2/ (2)^2
n=
138.297 rounded up to 139
<span>There
is not enough funds for this one
since you’ll need 139 pieces and it costs 10 a piece, you’ll need 1390.</span>
b.
90% confidence interval
n= {[(Zalpha/2)^2]*[sd]^2}/
se^2
n=
(1.645)^2*(12)^2/ (2)^2
n=98
There is enough
funds since 98 pieces for 10 a piece is equal to 980.
