Ch4- Correlation

Question 1

What information can we get from regression lines ?

Answer 1

1. gradient = change in y for each unit ↑ in x
2. y-intercept = initial value
3. interpolation only (within range of data)- x extrapolate (outside range)
4. predict y-value only

Question 2

Suggest the validity of using an equation of regression line of y on x to estimate the value of x.

Answer 2

• r line of y on x only used to estimate y
• need r line of x on y to estimate x