Question

Which of the following situations do notinvolve a discrete random variable? There may be more than one answer. (Note that you are only asked to identify the type of variable; you do not need to try to solve any of them.)

The average length of time a call to company
Q's helpline takes is 8.53 minutes. Assuming that the times are normally distributed and there is a 50% chance that a call lasts for less than 8.53 minutes, estimate the standard deviation.

500 people were surveyed on the number of pets they own. 27% of the people said that they owned no pets; 33% of the people said they owned dogs. If four of the surveyed people are selected at random, what is the probability that exactly one of them owns a dog?

An experiment consists of flipping coins and counting how many times the coin comes up heads. What is the probability that, in 17 flips, we will get 10 heads?

Students in Ms. Pearson's class have an average height of 40 inches,. What is the probability that a randomly-selected student will be more than 42 inches tall?

Answer 1

In first case, the average length of time a call to company takes is a random variable, but not a discrete variable. As here time is a continuous variable.

In second case, as there are 0,1,2,3 or 4 can be the values of the random variable that is number of person out of 4 that own a dog. So here that variable is a discrete variable.

Here in third case, number of heads are a discrete variable.

Here in fourth case, the height of person is a continuous variable, not a discrete variable.