Drag z so that the shaded area under the standard normal curve, to the left of z, is 0.8849. Find z to two decimals.
Normal distribution worksheet with answers
The IQ scores are normally distributed with mean 100 points and standard deviation 15 points. What fraction is above 115 points? Find P(X > x) as a decimal.
The masses of passengers with luggage are independent and normal with mean 85 kg and standard deviation 12 kg. Find the probability P that the total mass of 6 of them is below 524.7 kg. Round z to two decimals.
Drag z so that the shaded area under the standard normal curve, to the right of z, is 0.0228. Find z to two decimals.
The heights of adult men are normally distributed with mean 178 cm and standard deviation 7 cm. Find the value x below which 25% of them lie (the 25th percentile).
The battery lifetimes are normally distributed with mean 500 h and standard deviation 40 h. Find the value x below which 5% of them lie (the 5th percentile).
Answer key
- 1. z = 1.2
- 2. P(X > x) = 0.1587
- 3. P = 0.6915
- 4. z = 2
- 5. x = 173.3 cm
- 6. x = 434.2 h
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