STA108 WEEK 8

LEARNING OBJECTIVE 1:

Simple Linear Regression (Prediction)

Students need to know how to make prediction or estimation based on estimated regression equation.

👉🏼 Watch Video V1W8 above

👉🏼 Redo Example 4(f) Pg. 90

LEARNING OBJECTIVE 2:

Coefficient of Determination (R-Square)

Students need to know how to calculate and interpret the meaning of coefficient of determination, R2.

👉🏼 Refer Pg. 89 (formula)

👉🏼 Watch Video V2W8 above

👉🏼 Redo Example 4(e) Pg. 90

Please do the following exercises for better understanding of this topic:

EXAMPLE 5 (Pg. 91)

Answer:

a) X: Annual income       Y: Monthly insurance

b) r = 0.891 (There is a strong positive correlation between annual income and monthly insurance)

c) R2 = 79.39%

d) y = -147.4745 + 6.3074x

e) Slope, b = 6.3074 indicates that for every thousand increase in annual income of a personnel, their monthly insurance premiums will increase by RM6.31.

*In this example, it is not suitable to interpret value a (y-intercept)

f) RM 546.34

EXAMPLE 6 (Pg. 92)

Answer:

a) X: Batch Size        Y: Direct labor cost

b) r = 0.9996 (There is a very strong positive correlation between batch size and direct labor cost)

c) y = 18.5295 + 10.1545x

Slope, b = 10.1545 indicates that for additional unit of batch size, direct labor cost will increase by 10 .

d) 983.207

e) R2 = 99.92%

LEARNING OBJECTIVE 3:

Drawing Estimated Linear Regression Line

Students need to know how to draw the regression line on scatter plot.

👉🏼 Watch Video V3W8 above

👉🏼 Use scatter plot from Example 2(b), Pg. 86, try draw the regression line on the scatter plot.

👉🏼 Use scatter plot from Example 3(b), Pg.87, try draw the regression line on the scatter plot.