Answer:
Step-by-step explanation:
a)General least square regression line is ,
Where,a=intercept. b= slope
To get line just find values of a and b.
Use Excel to find values.
First enter values of variable "age" that is y in the column A that is A1to A5 and values of variable "height" in the column B, B1 to B5.
Then for value of a use functufuas ,
=INTERCEPT(A1:A5,B1:B5)
Then hit enter ,therefore a=20.4595
For b use function as. =SLOPE(A1:A5,B1:B5)
Then hit enter.therefore b=0.3738
Therefore equation of least square regression line is
Y=20.4595+(0.3738*x)
b) to predict height at age 21 years or 252 month just put value of x=252 in the above equation.
Y=20.4595+(0.3738+252)
Y=20.4595+94.1976
Y=114.6571
Conclusion: height will be 114.6571 inches when age change by 1 unit.