Question

studies have determined that the average gestation period (time between conception and giving birth) for humans to be nearly 266 days, while the standard deviation is about 16 days. assuming that the period of gestation is normally distributed, we can conclude that 95% of all pregnancies will last between and days.

Explanation:

Step1: Recall normal - distribution property

For a normal distribution, about 95% of the data lies within 2 standard deviations of the mean.

Step2: Calculate the lower bound

The mean $\mu = 266$ days and the standard deviation $\sigma=16$ days. The lower - bound is $\mu - 2\sigma$. So, $266-2\times16=266 - 32=234$ days.

Step3: Calculate the upper bound

The upper - bound is $\mu + 2\sigma$. So, $266+2\times16=266 + 32=298$ days.

Answer:

234, 298