Question

The mean length of a human pregnancy is 270 days, with a standard deviation of 14 days. Use the empirical rule to determine the percentage of women whose pregnancies are between 256 and 284 days. (Assume the data set has a bell-shaped distribution.)

Answer 1

Niyastokes, this is the solution:

Mean = 270

Standard deviation = 14

Let's recall that the Empirical rule states that 68% of the data falls within one standard deviation, in consequence:

270 +/- 14 =

270 - 14 = 256

270 + 14 = 284

The percentage of women whose pregnancies are between 256 and 284 days is 68%.