Understanding Z Scores and Probability with TI-84

This video tutorial demonstrates how to use the TI-84 calculator to find the probability that a Z score falls between two given values in a standard normal distribution. It explains the use of the normal CDF feature on the TI-84, detailing the steps to input the lower and upper Z score bounds, and how to interpret the results. The tutorial provides a clear, step-by-step guide to calculating the probability, emphasizing the importance of setting the mean (mu) to zero and the standard deviation (sigma) to one for standard normal distribution calculations.

What is the purpose of using the TI-84 calculator in this tutorial?

• To find the mean of a data set

• To determine the probability between two Z scores

• To calculate the standard deviation

• To graph a linear equation

Which feature of the TI-84 is used to find the probability between two Z scores?

• Normal PDF

• Normal CDF

• Standard Deviation

• Mean Calculation

What values do you need to input into the normal CDF feature?

• Variance and Range

• Mean and Median

• X, Y, Z, and T

• A, B, mu, and sigma

What are the values of mu and sigma set to for a standard normal distribution?

• Mu = 1, Sigma = 1

• Mu = 0, Sigma = 0

• Mu = 0, Sigma = 1

• Mu = 1, Sigma = 0

What is the lower bound Z score used in this example?

• 0.92

• 1.25

• -1.25

• -0.92

What is the upper bound Z score used in this example?

• -1.25

• 0.92

• 1.25

• -0.92

What is the final probability result as a decimal?

• 0.7156

• 0.5254

• 0.6254

• 0.8156

How is the probability result interpreted as a percentage?

• 52.54%

• 81.56%

• 62.54%

• 71.56%

What is the significance of the shaded region under the curve?

• It represents the variance

• It represents the standard deviation

• It represents the probability between two Z scores

• It represents the mean of the distribution

What is the first step in using the TI-84 to find the probability?

• Press second, vars for distribution

• Enter the mean and standard deviation

• Calculate the variance

• Graph the Z scores