If we are very certain that the true standard deviation of the number of defects per screen is below 2, what sample size would be required so that the width of the 95% confidence interval for the mean number of defects per screen is at most 0.27? make sure you enter a whole number below.

211

Step-by-step explanation:

As per given , we have

The true standard deviation:

Critical value for 95% confidence =

margin of error : E= 0.27

Formula to find the required sample size : -

hence, the required minimum sample =211

e.

step-by-step explanation:

because there are always 10 numbers in a phone number.

answer: expected value of x = 1.0

step-by-step explanation:

p(x=0) = 0.25

p(x=1) = 0.50

p(x=2) = 0.25

expected value for x = 0×0.25 + 1×0.5 + 2×0.25 = 1.0