Specifications for the shaft of an electric motor indicate the diameter of the shaft must be within 0.5±0.01 inches to be considered non-defective. data from inspectors indicate that currently, shaft diameters follow a normal distribution with mean m=0.505 and standard deviation s=0.005.
a) what fraction of shafts will be defective?
b) suppose the mean shifts to m=0.5, now what fraction of shafts will be defective?
c) suppose the mean stays at m=0.5, and you want to reduce the standard deviation so that 99.9% of the shafts are non-defective. what value of s will produce the desired result?

step-by-step explanation:

step 1: solve one of the equations for one of the variables. let's solve the first equation for y:

step 2: substitute that equation into the other equation, and solve for x.

step 3: substitute x = 4 x = 4 x=4 into one of the original equations, and solve for y.

answer:   expression= p+p*d%

price reduction + sale price = $625

sale price: $p+$p*d%

where d% is the percentage of discount

step-by-step explanation:

original price = p

price went down by $150 price reduction $p*d%

sale price= $ 475

therefore the price before sale is: $625

and the expression that shows the price before sale is: p+p*d%