Question

The weights of babies born at a certain large hospital are normally distributed

with an average of 7.5 pounds and a standard deviation of 1.25 pounds.
What range of weights would put a baby born at this hospital in the middle 50%
in terms of weight?

Answer 1

Option E

Step-by-step explanation:

Formula for the confidence interval here will be;

CI = x¯ ± zσ

Where;

x¯ is mean = 7.5 pounds

σ is standard deviation = 1.25

z is critical value at confidence interval of 50% = 0.674

Thus;

CI = 7.5 ± (0.674 × 1.25)

CI = (7.5 - (0.674 × 1.25)), (7.5 + (0.674 × 1.25))

CI ≈ (6.7, 8.3)

Thus,the range of weights is between 6.7 pounds and 8.3 pounds.