Mastering Correlation Coefficient and Line of Best Fit with TI 84

This video tutorial teaches how to use a calculator to find the line of best fit and the correlation coefficient. It begins with an introduction to these concepts, followed by a survey example where students' homework time and GPA are analyzed. The tutorial explains how to enter data into a calculator, calculate the line of best fit, and interpret the correlation coefficient, highlighting the relationship between the variables.

What is the primary purpose of the line of best fit?

• To identify outliers in a data set

• To find the average of a data set

• To calculate the median of a data set

• To determine the relationship between two variables

What does the correlation coefficient (r) indicate?

• The average value of the data

• The total number of data points

• The strength and direction of the relationship between two variables

• The difference between the highest and lowest values

How many students were surveyed in the example provided?

• Twenty

• Three

• Five

• Ten

What were the two questions asked in the survey?

• How many hours do you sleep? and What is your GPA?

• How many minutes do you spend on your homework? and What is your GPA?

• How many hours do you study? and What is your favorite subject?

• How many minutes do you spend on your homework? and What is your favorite subject?

What should you do if there are existing numbers in the list before entering new data?

• Skip entering new data

• Turn off the calculator

• Highlight the list and press clear and enter

• Delete the entire list

Where do you enter the x values in the calculator?

• In L2

• In L3

• In L1

• In L4

What is the format of the equation provided by the line of regression?

• y = cx + d

• y = bx + a

• y = ax + b

• y = mx + c

What should you do if the correlation coefficient does not show up in the calculator?

• Turn on the diagnostic feature

• Reset the calculator

• Re-enter the data

• Turn off the calculator

How do you turn on the diagnostic feature in the calculator?

• Go to second and then catalog, scroll to D, and select diagnostic on

• Press the reset button

• Enter the data again

• Turn off the calculator and turn it on again

What does an r value of 0.933 indicate?

• No correlation

• A strong correlation

• A weak correlation

• A negative correlation