Normal Distribution and Z-Scores

This video tutorial demonstrates how to use the TI-84 calculator to determine the probability of a student scoring above 80 on a normally distributed exam. It covers modeling the normal distribution, using the normalcdf function on the TI-84, and calculating z-scores. The tutorial also explains how to interpret results using both the normal and standard normal distribution curves.

What is the mean score of the class exam mentioned in the video?

• 83

• 80

• 76

• 70

Where would a test score of 80 be located on the normal distribution curve?

• Between 83 and 90

• Between 90 and 97

• Between 69 and 76

• Between 76 and 83

Which function on the TI-84 calculator is used to find the probability of a score being greater than a certain value?

• normalpdf

• normalcdf

• invNorm

• binomcdf

What is the lower bound when calculating the probability of scoring more than 80 using the TI-84?

• 80

• 76

• 83

• 99999

What is the z-score formula used in the video?

• (x - mu) / sigma

• (x + mu) / sigma

• (mu - x) / sigma

• (sigma - x) / mu

What is the z-score for a test score of 80?

• 0.2839

• 1.1428

• 0.5714

• 0.7142

In the standard normal distribution, what is the mean value?

• 1

• 0

• 7

• 76

What is the standard deviation in the standard normal distribution?

• 76

• 1

• 0

• 7

How is the probability related to the area under the curve in a normal distribution?

• It is half of the area under the curve

• It is unrelated to the area under the curve

• It is equal to the area under the curve

• It is twice the area under the curve

If using a table instead of a calculator, what must be used to determine the probability?

• Mean

• Z-score

• Standard deviation

• Raw score