Linear Correlation and Regression

Question 1

_______________________ (PCC)

Answer 1

Pearson Correlation Coefficient

Question 2

Correlation
•shows the __________ between two variables
•the _______ of ________ between the two variables
• The two variables should be _______

Answer 2

Co-relationship

Strength of relationship

numeric

Question 3

Linear Correlation and Regression
• Linear mean __________
• For ___________ it does not really matter which of the variable is independent or dependent
• For ___________ it matters, there will be an independent variable and a dependent variable

Answer 3

straight line

correlation

Regression

Question 4

On a straight line, the perfect linear relationship, has the highest value of correlation coefficient which is equal to ________

Answer 4

1

Question 5

Linear Correlation and Regression
• In real life, we have the perfect linear relationship

T/F

Answer 5

F

• In real life, we don’t have perfect linear relationship

Question 6

Linear Correlation and Regression

• Lowest value of correlation coefficient is ________
• The value -0.7 and 0.7 are of same strength but __________

Answer 6

zero

in different direction

Question 7

In positive Correlation, The variables ________________ (as one variable is ________ ,the other variable is _________

Answer 7

move in the same direction

increasing

also increasing.

Question 8

In Negative Correlation , The variables are in _________ direction

Answer 8

opposite

Question 9

Small letter r= _____________ coefficient
• rho = ____________ coefficient

Answer 9

sample correlation

population correlation

Question 10

Regression Coefficient

• Predict one variable from ___________________________

Answer 10

the knowledge of another biological measurement

Question 11

Regression Coefficient

• Dependent variable: The variable you __________ (The _________ variable)

• Independent e.g. _____

Answer 11

want to predict; Outcome

Age

Question 12

Regression Coefficient
• Regression coefficient = _____
• It is telling us the amount of ___________ per unit _______

Answer 12

b

change in y ; change in x

Question 13

Linear equation of a straight line

y =_________

Answer 13

a+bx

Question 14

Y= a + bx

• a= _______ ( Value of ___ when ________ )
• b= _____ (___________ )

Answer 14

intercept; y; x =0

slope

regression coefficient

Question 15

Columns needed in calculating linear correlation and regression?

Answer 15

x- x

(x- x)^2

(y-y)

(y-y)^2

(x- x)(y-y)

Question 16

Both regression and correlation coefficient have the same __________

Answer 16

numerator

Question 17

Numerator of both correlation and regression is ???

Answer 17

Σ (x- x) (y-y)

Question 18

Denominator for r (__________ coefficient ) is ??

Answer 18

correlation

= √( Σ(x- x)^2 (Σ (Y-Y)^2)

Question 19

Denominator for b (__________ coefficient ) is ?

Answer 19

Regression

Σ(x- x)^2

Question 20

r is generally considered strong when r value is > _____

Answer 20

0.7

Question 21

A simple guide to interpreting r
• ____-_____ =Poor
• ____-_____ =weak
• ____-_____ = Moderate
• ____-_____ = strong.

NB: r larger than ______ is generally considered strong.

Answer 21

• 0- 0.25 =Poor
• 0.26-0.50 =weak
• 0.51 - 0.75 = Moderate
• 0.76 – 1.0 = strong.

strong.