T2 Practice

Determine whether the following table represents a valid discrete probability distribution.

• Yes, because the probabilities sum up to 1 AND the probabilities are between 0 & 1.

• No, because the probabilities do not sum up to 1, even though all the probabilities are between 0 & 1.

• Yes, because each probability is between 0 and one, even though the probabilities do not sum up to 1.

• No, because one of the probabilities is greater than 1.

Fill in the missing value so that the following table represents a probability distribution.

Find the probability a randomly selected contestant received 3 points.

• 0.03

• 0.14

• 0.52

• 0.17

Find the probability a randomly selected contestant received at least 3 points.

• 0.77

• 0.91

• 0.24

• 0.69

Find the probability a randomly selected contestant received at least 1 point.

• 0.97

• 0.88

• 0.83

• 0.76

What is the mean of the probability distribution for the scores given by a judge at a talent show?

• 1.07

• 2.98

• 2.5

• 0.17

What will the z-score be for a value that is 3 standard deviations above the mean?

• 1

• 0

• 3

• -3

What is the probability that a randomly chosen woman has exactly three children according to the probability histogram provided?

• 0.160

• 0.154

• 0.273

• 0.244

Using the information from the probability density curve provided, find the proportion of batteries with lifetimes that last longer than 20 months.

• 0.57

• 0.43

• 0.29

• 0.14

Find the area under the standard normal curve to the right of (greater than) z = -1.5.

• 0.9332

• 0.0668

• 0.1292

• 0.8708