Questions from Engineering Statistics

Q: It is estimated that 4000 of the 10,000 voting residents

It is estimated that 4000 of the 10,000 voting residents of a town are against a new sales tax. If 15 eligible voters are selected at random and asked their opinion, what is the probability that at mo...

Q: Repeat Exercise 4.62 if X and Y are not independent

Repeat Exercise 4.62 if X and Y are not independent and σXY = 1. Exercise 4.62: If X and Y are independent random variables with variances σ2X = 5 and σ2Y = 3, find the variance of the random variabl...

Q: Suppose that X and Y are independent random variables with probability densities

Suppose that X and Y are independent random variables with probability densities and and Find the expected value of Z = XY .

Q: Let X represent the number that occurs when a red die is

Let X represent the number that occurs when a red die is tossed and Y the number that occurs when a green die is tossed. Find (a) E(X + Y ); (b) E(X − Y ); (c) E(XY ).

Q: Let X represent the number that occurs when a green die is

Let X represent the number that occurs when a green die is tossed and Y the number that occurs when a red die is tossed. Find the variance of the random variable (a) 2X − Y; (b) X + 3Y − 5.

Q: If the joint density function of X and Y is given

If the joint density function of X and Y is given by find the expected value of

Q: The power P in watts which is dissipated in an electric circuit

The power P in watts which is dissipated in an electric circuit with resistance R is known to be given by P = I2R, where I is current in amperes and R is a constant fixed at 50 ohms. However, I is a r...

Q: Consider Review Exercise 3.77 on page 108. The random

Consider Review Exercise 3.77 on page 108. The random variables X and Y represent the number of vehicles that arrive at two separate street corners during a certain 2-minute period in the day. The joi...

Q: By investing in a particular stock, a person can make a

By investing in a particular stock, a person can make a profit in one year of $4000 with probability 0.3 or take a loss of $1000 with probability 0.7. What is this person’s expected gain?

Q: Consider Review Exercise 3.64 on page 107. There are

Consider Review Exercise 3.64 on page 107. There are two service lines. The random variables X and Y are the proportions of time that line 1 and line 2 are in use, respectively. The joint probability...