math
posted by darlene on .
a factory produces 150,000 lightbulbs per day. the manager of the factory estimates that fewer than 1,000 defictive bulbs are produced each day . in a random sample of 250 lightbulbs , there are 2 defictive bulbs . determine whether the managers estimate is likely to be accurate. explain.

% Estimated=(1000/150000) * 100%=0.67 %
% Defective = (2/250) * 100% = 0.8 %.
(0.8% /0.67%) * 100% = 119%.
119%  100% = 19 %.
The actual % is about 19% higher than the estimated %. 
Set up the proportion 150,000 over x= 250 over two. Cross multiply 150000 and two to get 300000. Set up the equation 300,000=250x. Divide both sides with 250 to get the answer.