Calculating Mean and Standard Deviation

The video tutorial explains how to find cutoff scores for test results that are normally distributed. It uses a graphing calculator to determine the cutoff score for the 70th percentile, given a mean of 75 and a standard deviation of 15. The process involves using the calculator's distribution function to input the area to the left (0.7 for the 70th percentile), the mean, and the standard deviation. The tutorial concludes by identifying the score that separates the lower 70% from the upper 30%, which is 83.

What is the mean of the example test scores mentioned in the video?

• 85

• 80

• 75

• 70

What is the standard deviation of the test scores in the example?

• 10

• 15

• 12

• 18

Which percentile are we trying to find the cutoff score for?

• 65th

• 70th

• 60th

• 75th

What is the first step in finding the cutoff score using a graphing calculator?

• Press Enter

• Enter the mean

• Enter the standard deviation

• Go to 2nd distr

Which option should you select after accessing the '2nd distr' menu?

• Number three

• Number one

• Number two

• Number four

Which function on the calculator is used to find the cutoff score?

• Norm function

• Percentile function

• Mean function

• Standard deviation function

What value should be entered for the area to the left when finding the 70th percentile?

• 0.8

• 0.5

• 0.6

• 0.7

After entering the area, what is the next value to input?

• The standard deviation

• The mean

• The percentile

• The median

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

• Re-enter the values

• Press Enter

• Press the reset button

• Close the calculator

What is the purpose of entering the mean and standard deviation in the calculator?

• To identify the mode

• To find the median

• To calculate the average

• To determine the cutoff score