A telephone survey of American families is conducted to determine the number of children in the average American family. Past experience has shown that 30% of the families who are telephoned will refuse to respond to the survey. Which of the following statements is not a binomial random variable?
A) The number of families out of 50 who respond to the survey.
B) The number of families out of 50 who refuse to respond to the survey.
C) The number of children in a family which responds to the survey.
D) All of these are binomial random variables.
E) None of these is a binomial random variable.

Question

Quizplus · Accepted Answer

The number of children in a family which responds to the survey is not a binomial random variable because it does not have a fixed number of trials with a binary outcome (success or failure). The other options all have a fixed number of trials (50 families surveyed) with a binary outcome (responding or not responding).

A Telephone Survey of American Families Is Conducted to Determine