Question

9. [ 8 points ] The lengths of human pregnancies are approximately normally distributed, with mean ? = 266 days and standard deviation ? = 16 days. (a) What proportion of pregnancies lasts at least 270 days? (b) Determine the minimum length of human pregnancies that are in the longest 5% of all human pregnancies.

          9. [ 8 points ] The lengths of human pregnancies are approximately normally distributed, with mean ? = 266 days and standard deviation ? = 16 days.

(a) What proportion of pregnancies lasts at least 270 days?

(b) Determine the minimum length of human pregnancies that are in the longest 5% of all human pregnancies.

9. [ 8 points ] The lengths of human pregnancies are approximately normally distributed, with mean ? = 266 days and standard deviation ? = 16 days.

(a) What proportion of pregnancies lasts at least 270 days?

(b) Determine the minimum length of human pregnancies that are in the longest 5% of all human pregnancies.

Added by Brandon G.

Elementary Statistics a Step by Step Approach

Allan G. Bluman 9th Edition

Instant Answer

Solved by Expert Adi S

09/19/2023

Step 1

The z-score is calculated as: z = (X - μ) / σ where X is the value we're interested in (270 days), μ is the mean (266 days), and σ is the standard deviation (16 days). z = (270 - 266) / 16 = 4 / 16 = 0.25 Now, we need to find the proportion of pregnancies that Show more…

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9. [ 8 points ] The lengths of human pregnancies are approximately normally distributed, with mean μ = 266 days and standard deviation σ = 16 days. (a) What proportion of pregnancies lasts at least 270 days? (b) Determine the minimum length of human pregnancies that are in the longest 5% of all human pregnancies.