Question

The length of a screw produced by a machine is normally distributed with a mean of 0.55 inches and a standard deviation of 0.01 inches. What percent of screws are between 0.53 and 0.57 inches?

99.7%

68%

95%

100%

Answer 1

:( I just have no idea how to do this

Answer 2

u can do it in two ways,

Answer 3

if u remember 68-95-99.7 rule :
68% of observations lie within 1 standard deviation
95% of observations lie within 2 standard deviations
99.7% of observations lie within 3 standard deviations

Answer 4

so is it 68%??

Answer 5

0.03 is 2 standard deviations