Understanding Cumulative Normal Probability

The video tutorial explains how to find cumulative normal probability using tables. It begins by introducing the concept and then demonstrates converting a random variable to a standard normal variable. The tutorial calculates the probability of X being greater than 13 by using the Z value and explains how to use cumulative normal probability tables. It concludes with calculating the required probability of Z being greater than 1.5 and provides a step-by-step guide to understanding the process.

What is the initial value of the random variable X in the given problem?

• 20

• 15

• 13

• 10

What is the mean value used in the problem setup?

• 8

• 14

• 10

• 12

What is the standard deviation value assumed in the problem?

• 3

• 2

• 1

• 4

How is the standard normal variable calculated from the random variable?

• By dividing the random variable by the mean

• By multiplying the random variable by the standard deviation

• By adding the mean to the random variable

• By subtracting the mean from the random variable and dividing by the standard deviation

What is the Z value corresponding to X = 13 in this problem?

• 2.0

• 1.5

• 1.0

• 0.5

What does the cumulative normal probability table provide?

• Probability of Z less than a value

• Probability of Z greater than a value

• Probability of Z not equal to a value

• Probability of Z equal to a value

What is the cumulative probability value for Z = 1.5 from the table?

• 0.250

• 0.750

• 0.500

• 0.933

How do you find the probability of Z greater than 1.5?

• By dividing the cumulative probability by 2

• By multiplying the cumulative probability by 2

• By subtracting the cumulative probability from 1

• By adding 0.5 to the cumulative probability

What is the total area under the normal distribution curve?

• 0.5

• 1.0

• 1.5

• 2.0

What is the probability of Z less than 0?

• 0.75

• 0.5

• 1.0

• 0.25