Question

A shipment of marbles with a mean diameter of 27 mm and a standard deviation of 0.15 mm is normally distributed. By how many standard deviations does a marble with a diameter of 26.85 mm differ from the mean?

Answer 1

The answer would be 1

Explanation:

Answer 2

This could be solved by calculating the z-score. Its definition is the number of standard deviations from the mean a data point is. The formula is,

Z =║Data point – Mean║ / Std. dev.

Z = ║26.85 mm – 27 mm║ / 0.15

Z = 1