Birth weights of babies born to full-term pregnancies follow roughly a Normal distribution.At Meadowbrook Hospital,the mean weight of babies born to full-term pregnancies is 7 pounds with a standard deviation of 14 ounces (1 pound = 16 ounces). What is the probability that the average weight of the four babies will be more than 7.5 pounds?
A)0.0065
B)0.1265
C)0.2839
D)0.4858

Question

Quizplus · Accepted Answer

First, we convert the given mean weight of 7 pounds to ounces: 7 pounds = 7 x 16 ounces = 112 ounces.

Next, we need to find the probability that the average weight of the four babies will be more than 7.5 pounds or 7.5 x 16 = 120 ounces.

To do this, we need to calculate the z-score and look up the corresponding probability in a standard Normal distribution table.

z-score = (sample mean - population mean) / (standard deviation / square root of sample size)

z-score = (120 - 112) / (14 / sqrt(4)) = 4/7

Using a standard Normal distribution table (or calculator), we can find that the probability of a z-score being greater than 4/7 is 0.1265.

Therefore, the answer is B.

Birth Weights of Babies Born to Full-Term Pregnancies Follow Roughly