Question

Imagine a regression line that relates y = average systolic blood pressure to x = age. The average blood pressure for people 40 years old is 110, while for those 50 years old the average is 130. (a) What is the slope of the regression line? (Round the answer to one decimal place.)

Answer 1

2.0

Explanation:

x = age

y = average systolic blood pressure

x₁ = 40 years old, y₁ = 110 systolic blood pressure

x₂ = 50 years old, y₂ = 130 systolic blood pressure

`\text{Slope of a line}=m=(y_2-y_1)/(x_2-x_1)\\\Rightarrow m= (130-110)/(50-40)\\\Rightarrow(20)/(10)\\\Rightarrow m= 2.0`

∴ Slope of the regression line is 2.0