Correlation & Regression

Question 1

What is a correlation

Answer 1

The degree of association between two variables

Question 2

What is a positive correlation

Answer 2

If one of the variables increases, the other does too

Question 3

What is no correlation?

Answer 3

When there is no association between the two variables

Question 4

What is a negative correlation?

Answer 4

If one variable decreases, then the other one increase

Question 5

In regards to correlation coefficient what is the perfect negative correlation?

Answer 5

r = -1

Smaller the value the weaker the correlation

Question 6

In regards to correlation coefficient what is the perfect positive correlation

Answer 6

r = +1

The larger that value the stronger the correlation

Question 7

In regards to correlation coefficient what is no correlation?

Answer 7

r = 0

Question 8

What is an independent variable and where is it plotted?

Answer 8

x axis

It is the basis of our prediction

Question 9

What is a dependent variable and where is it plotted?

Answer 9

y axis

The variable that we want to predict

Question 10

What does the correlation coefficient measure?

Answer 10

The relationship but not the causation

Question 11

How do you calculate the regression line using a calculator?

Answer 11

Mode - Stat - A+BX
Shift - 1 - REG
A & B

Question 12

How do you calculate the correlation coefficient using a calculator?

Answer 12

Mode - Stat - A+BX
Shift - 1 - REG
r

Question 13

In regards to the regression line, how do you work out it out for a specific time period, etc etc?

Answer 13

1. Get the regression line for the data given
2. Then its:
   time to pay (b) x _____ x previous regression total