expected value of a normal distribution help

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 resulting s..

A survey asks 'How much time do you spend in front of the TV in one week? Suppose the responses are normally distributed, the mean is 10 hours and the standard deviation is 2 hours. Suppose there are 50 responses to the survey question. How many would you expect to spe..

Assume that the weights of 3,000 students at a university are normally distributed with mean 150 pounds and a standard deviation of 2.72 pounds. How many samples would you expect to find the mean between 147 and 155 pounds? => 83 or 82 or 84 or 81..

The full term birth weight of babies in a hospital is normally distributed with a mean of 3.0 kg and a standard deviation of 0.5 kg. If 300 babies were weighed, about how many of them would be expected to weigh between 2.5 to 3.5 kg? => 250 or 200 or 205 or 100..

If x is a discrete random variable assuming the values x 1 , x 2 , x 3 ,….,x n with probabilities p 1 , p 2 , p 3 ,…., p n respectively then (x 1 ,p 1 ), (x 2 , p 2 ),…(x n , p n ) defines a probability distribution of X. Mathematical Expectationh..

Find the area under the normal distribution curve shown in the figure. => 15.59% or 9.01% or 84.41% or 94.41%..

For any specific value of the independent variable, the values of the dependent variable y are normally distributed. This is called the __________ assumption. => independence or linearity or equal - variance or normality..

The local authorities in a certain city install 1600 electric lamps in the streets of the city. If the lamps have a mean life rate of 1000 burning hours, with a standard deviations of 150 hours, find the value of - 2 standards deviations form the mean. Assume that the lines of the lamps a..

Find two z values, which bound 50% of the exact middle area of a standard normal distribution. => - 0.674, + 0.674 or - 0.674, + 4.0 or - 4.0, + 4.0 or - 4.0, + 0.674..

What is the z value so that 95% of the area under the normal distribution curve lies to the left of it? => - 1.645 or 0.13 or 1.736 or 1.645..