A shipment of ball bearings with a mean diameter of 25 mm and a standard deviation of 0.2 mm is normally distributed. By how many standard deviations does a ball bearing with a diameter of 25.6 mm differ from the mean?

Question

SmokeyBrown · Answer

One standard deviation is 0.2 mm, according to the question.
And the question also tells us that the mean in this case is 25 mm.
A ball bearing with 25.6 mm is different from the mean by 0.6 mm.
So, how many standard deviations is this 0.6 mm difference?