Assume that the duration of human pregnancies can be described by a normal model with mean 266 days and standard deviation 16 days.
what percentage of pregnancies should last between 270 and 280 days?

21.05%

Step-by-step explanation:

First find the z-score  for both 270 and 280 days of pregnancy and their equivalent percentile in the normal distribution.

For X = 270 days:

A z-score of 0.25 corresponds to the 59.871 th percentile

Therefore, 59.871% of pregnancies should last less than 270 days.

For X = 280 days:

A z-score of 0.875 corresponds to the 80.921 th percentile

100 - 80.921 = 19.079

Therefore, 19.079% of pregnancies should last more than 270 days.

The percentage of pregnancies lasting  between 270 and 280 days (P) is given by:

P=100 -19.079-59.871

P=21.05%

answer: if you weigh 60 pounds on earth, on the moon you will weigh about 10 pounds. if you weigh 120 pounds on earth, you will weigh about 20 pounds on the moon. since weight is caused by the mass of two objects that are near each other, the bigger the objects, the more the force of gravity.

step-by-step explanation: if you weigh 60 pounds on earth, on the moon you will weigh about 10 pounds. if you weigh 120 pounds on earth, you will weigh about 20 pounds on the moon. since weight is caused by the mass of two objects that are near each other, the bigger the objects, the more the force of gravity.