normal distribution

The average age of the employees in an organization is 34 years. Assume the variable is normally distributed and the standard deviation is 4 years. If 30 employees are selected at random, then find the probability that the mean age of the employees is greater than 32 years. => 0..

The average protein content in different types of nuts is 20 g, and the standard deviation is 5 g. Assume the variable is normally distributed. If a sample of 16 nuts are selected, then find the probability that the mean of the sample will be greater than 22 g. => 65.54% or 34.4..

Select the correct statement(s) on the standard normal distribution curve. I. The curve is sinusoidal (of the shape of sine curve). II. It is unimodal. III. The mean, median and mode are equal. IV. Area under the curve is assumed as 1. => II and IV only or III and IV only or II,..

An economist wishes to estimate the average monthly rent of houses in a large city to within $25 with 99% confidence. A study of 70 houses in the city found that 49 houses had their rent as $1,000. How many houses must be surveyed in order to be justified in assuming that the sample proportion is a..

Assuming that the weights of the girls in a class are normally distributed with a mean of 50 kg and a standard deviation of 3.5 kg, find the percentage of girls with a weight in between 50 kg and 53.5 kg. => 87% or 34% or 47.5% or 68%..

The cholesterol level of healthy men is normally distributed with a mean of 190 mg/dL and a standard deviation of 15. At what level (in excess of 190 mg/dL) should men be diagnosed as not healthy if the probability of a type I error is 2.5%? => 160.6 or 219.4 or 205 or 175..

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? => 150 lbs, 7 10 lbs or 150..

Say whether the normal distribution can be used as an approximation to the binomial distribution shown here. n = 30 and p = 0.5 => cannot be determined or true or false..

As the sample size n increases without limit, the shape of the distribution of the sample means taken with replacement from a population with mean μ and standard deviation σ will approach a normal distribution. This distribution will have mean μ a..

The mean lifetime of a clock is 30 months. If the distribution is normal with a standard deviation of 4 months, then for how many months should a guarantee be made if the manufacturer does not want to exchange more than 5% of the clocks? => 23 months or 24 months or 20 months or..