Exam 6: The Normal Distribution and Other Continuous Distributions

The amount of time necessary for assembly line workers to complete a product is a normal random variable with a mean of 15 minutes and a standard deviation of 2 minutes.The probability is ________ that a product is assembled in less than 12 minutes.

The probability that a standard normal variable Z is positive is ________.

Instruction 6-5 Suppose the time interval between two consecutive defective light bulbs from a production line has a uniform distribution over an interval from 0 to 90 minutes. -Referring to Instruction 6-5,what is the mean of the time interval?

The amount of time necessary for assembly line workers to complete a product is a normal random variable with a mean of 15 minutes and a standard deviation of 2 minutes.The probability is ________ that a product is assembled in more than 11 minutes.

Instruction 6-4 John has two jobs.For daytime work at a jewelry store he is paid $15,000 per month,plus a commission.His monthly commission is normally distributed with mean $10,000 and standard deviation $2,000.At night he works as a waiter,for which his monthly income is normally distributed with mean $1,000 and standard deviation $300.John's income levels from these two sources are independent of each other. -Referring to Instruction 6-4,for a given month,what is the probability that John's commission from the jewelry store is between $9,000 and $11,000?

When p is not equal to 0.5,the binomial distribution is not symmetrical,however,the closer the p is to 0.5 and the larger the sample size,the more symmetrical the distribution is.

A worker earns $15 per hour at a plant and is told that only 2.5% of all workers make a higher wage.If the wage is assumed to be normally distributed and the standard deviation of wage rates is $5 per hour,the average wage for the plant is $7.50 per hour.