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 is less than a given value in a standard normal distribution. It covers the use of the normal CDF function, setting lower and upper bounds, and interpreting the results. The tutorial provides a step-by-step guide to inputting values and understanding the output, emphasizing the importance of setting appropriate bounds for accurate probability calculations.

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

• To calculate the mean of a data set

• To determine the probability of a z-score being less than a given value

• To find the median of a data set

• To solve linear equations

In a standard normal distribution, what does the area under the curve to the left of a z-score represent?

• The mean of the distribution

• The probability of the z-score

• The standard deviation

• The mode of the distribution

Which feature on the TI-84 calculator is used to find the probability of a z-score?

• NormalCDF

• NormalPDF

• StatPlot

• InvNorm

What values are entered into the normal CDF function to calculate probability?

• Lower and upper bounds, mean, and standard deviation

• Mean and median

• Variance and interquartile range

• Mode and range

What is the typical lower bound z-score used in this tutorial?

• 0

• 1.64

• -99,999

• 3

Why is a very low value like -99,999 used as the lower bound z-score?

• To match the upper bound

• To ensure all area to the left is included

• To simplify calculations

• To avoid errors in the calculator

What should the values of mu and sigma be set to for standard normal distribution calculations?

• Mu = 1, Sigma = 0

• Mu = 0, Sigma = 1

• Mu = 1, Sigma = 1

• Mu = 0, Sigma = 0

What is the probability that z is less than 1.64, as calculated in the tutorial?

• 0.105

• 0.9495

• 0.75

• 0.5

How is the probability result interpreted as a percentage?

• Approximately 10.5%

• Approximately 75%

• Approximately 94.95%

• Approximately 50%

What is the final step after entering all values in the TI-84 calculator?

• Resetting the calculator

• Pressing the 'Graph' button

• Turning off the calculator

• Pressing 'Enter' to calculate the probability