The heights of adult men are normally distributed with mean 178 cm and standard deviation 7 cm. What fraction is above 192.35 cm? Find P(X > x) as a decimal.
Normal distribution worksheet with answers
Drag z so that the shaded area under the standard normal curve, to the left of z, is 0.3745. Find z to two decimals.
The masses of bolts are independent and normal with mean 40 g and standard deviation 1.2 g. Find the probability P that the total mass of 12 of them exceeds 484.2 g. Round z to two decimals.
The IQ scores are normally distributed with mean 100 points and standard deviation 15 points. What fraction lies between 70 and 130 points? Give P as a decimal.
The exam scores are normally distributed with mean 65 points and standard deviation 10 points. Drag the cut-off so the shaded bottom 80% is to the left of it. Find the cut-off x.
The IQ scores are normally distributed with mean 100 points and standard deviation 15 points. Drag the cut-off so the shaded top 85% is to the right of it. Find the cut-off x.
Answer key
- 1. P(X > x) = 0.02018
- 2. z = −0.32
- 3. P = 0.1562
- 4. P = 0.9545
- 5. x = 73.4 points
- 6. x = 84.4 points
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