Question

 

1) The lengths of pregnancies in a small rural village are normally distributed with a mean of 265 days and a standard deviation of 14 days.
In what range would you expect to find the middle 98% of most pregnancies?
Between___ and ___ .
If you were to draw samples of size 53 from this population, in what range would you expect to find the middle 98% of most averages for the lengths of pregnancies in the sample?
Between ____ and _____.

2) Engineers must consider the breadths of male heads when designing helmets. The company researchers have determined that the population of potential clientele have head breadths that are normally distributed with a mean of 6.9-in and a standard deviation of 0.8-in.
In what range would you expect to find the middle 50% of most head breadths?
Between_____ and____ .
If you were to draw samples of size 48 from this population, in what range would you expect to find the middle 50% of most averages for the breadths of male heads in the sample?
Between ____ and____ .

Answer 1

1)

(b)

 

2: