Exam 8: Continuous Probability Distributions

If the mean of an exponential distribution is 2, then the value of the parameter $\lambda$ is 2.0.

Which of the following distributions is not skewed?

The probability that Z is less than -2 is the same as one minus the probability that Z is greater than +2.

Which of the following statements is false?

The mean of a Student t distribution is ____________________.

Use the F table to find the following values of F. a.F_.99,12,20 b.F_.95,20,40 c.F_.975,5,15 d.F_.99,8,30

If the random variable X is exponentially distributed and the parameter of the distribution $\lambda$ = 4, then P(X $\le$ 1) = 0.25.

Suppose X has a chi-squared distribution with 10 degrees of freedom. The variance of X is:

NARRBEGIN: Checking Accounts Checking Accounts A bank has determined that the monthly balances of the checking accounts of its customers are normally distributed with an average balance of $1,200 and a standard deviation of $250.NARREND -{Checking Accounts Narrative} What proportion of customers have monthly balances more than $1,125?

The Student t distribution with parameter v = 4 has a variance V(t) equal to:

A random variable X has a normal distribution with a mean of 250 and a standard deviation of 50. Given that X = 175, its corresponding value of Z is -1.50.

If the random variable X is exponentially distributed with parameter $\lambda$ = 3, then the probability P(X $\ge$ 2) equals:

The value of A such that P(-A $\le$ t $\le$ A) = 0.95, where the degrees of freedom are 20, is 2.086.

NARRBEGIN: Checking Accounts Checking Accounts A bank has determined that the monthly balances of the checking accounts of its customers are normally distributed with an average balance of $1,200 and a standard deviation of $250.NARREND -{Checking Accounts Narrative} What proportion of customers have monthly balances between $950 and $1,075?

If the random variable X has a uniform distribution between 40 and 50, then P(35 $\le$ X $\le$ 45) is:

If the random variable X is exponentially distributed with parameter $\lambda$ = 5, then the variance of X, $\sigma$ ² = V(X) = 0.04.

If the parameter of an exponential distribution is 1, then which of the following is not true?

If the random variable X is exponentially distributed with parameter $\lambda$ = 4, then the probability P(X $\le$ 0.25), up to 4 decimal places, is

If X is a continuous random variable on the interval [0, 10], then P(X > 5) = P(X $\ge$ 5).

NARRBEGIN: Counter Sales Counter Sales Suppose that customers arrive at a counter at an average rate of three customers per minute and that their arrivals follow the Poisson model.NARREND -{Counter Sales Narrative} Use the appropriate exponential distribution to find the probability that the next customer will arrive within 1.5 minutes.