Suppose that diameters of a new species of apple have a bell-shaped distribution with a mean of 7.19 cm and a standard deviation of 0.38 cm. Describe where approximately 99.7% of apple diameters lie.

Question

A) below 6.81 and above 7.57
B) below 6.05 and above 8.33
C) below 6.43 and above 7.95
D) between 6.05 and 8.33

Answer 1

D) between 6.05 and 8.33

This is because 99.7% of values lie within 3 standard deviations of the mean in a bell-shaped distribution. So, approximately 99.7% of apple diameters lie between 7.19 - (3*0.38) and 7.19 + (3*0.38), which is between 6.05 and 8.33.