standard normal distribution pdf

What percentage of area (approximately) under the normal distribution curve lies between a standard deviation of 1 and 2? => 15% or 13% or 27% or 30%..

Find the lowest control limit for a normally distributed curve with a mean of 15 and a standard deviation of 2.5. => 12.5 or 10 or 7.5 or 22.5..

The average price of a computer is $750. If prices of computers are approximately normally distributed with a standard deviation of $75, then what would be the maximum price of 10% of least-expensive computers? => $654 or $754 or $745 or $645..

The average price of a computer is $750. If prices of computers are approximately normally distributed with a standard deviation of $75, then what is the probability that a randomly selected computer costs more than $1000? => 3.3% or 0.33% or 0.04% or 0.4%..

The scores made by candidates in a certain test are normally distributed with mean 500 and standard deviation 100. What is the percentage of candidates who scored less than 400? => 15.87% or 17.85% or 18.57% or 15.78%..

The scores made by candidates in a certain test are normally distributed with mean 500 and standard deviation 100. What percentage of candidates received scores which differ from 500 by more than 150 points? => 43.23% or 13.36% or 43.32% or 6.68%..

The average price of a bicycle is $300. The prices of the bicycles are normally distributed with a standard deviation of $60. What is the probability that a randomly selected bicycle costs more than $450? => 0.62% or 6.2% or 3.8% or 0.38%..

Which statement is the characteristic of the t distribution that are not for the standard normal distribution? => The variance is greater than 1. or The mean, median and mode are equal to 0 and are located at the center of distribution. or The ..

The standard deviation of the hemoglobin values (g/100ml) of 10 children is 1.7. Find the 99% confidence interval for the variance and standard deviation. Assume that the variable is normally distributed. => 1.26 < σ 2 < 14.75 ; 1.12 < σ ..

Assume that the weights of 3,000 students at a university are normally distributed with mean 150 pounds and a standard deviation of 7 pounds. If 100 samples of 30 students each are obtained, then what would be the expected mean and standard deviation of the r..