Drag z so that the shaded area under the standard normal curve, to the left of z, is 0.0322. Find z to two decimals.
Normal distribution worksheet with answers
The delivery times are normally distributed with mean 32 min and standard deviation 6 min. What fraction is above 29 min? Find P(X > x) as a decimal.
The masses of boxes are independent and normal with mean 12 kg and standard deviation 0.8 kg. Find the probability P that the total mass of 16 of them is below 196.8 kg. Round z to two decimals.
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 10 of them is below 869 kg. Round z to two decimals.
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.
The bag weights are normally distributed with mean 250 g and standard deviation 5 g. Find the value x below which 25% of them lie (the 25th percentile).
Answer key
- 1. z = −1.85
- 2. P(X > x) = 0.6915
- 3. P = 0.9332
- 4. P = 0.6915
- 5. x = 84.4 points
- 6. x = 246.6 g
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