Solve using trigonometry
tan(39)=24/b
b=24/tan(39)
so b=29.6
for c…
sin(39)=24/c
c=24/sin(39)
c=38.1
Answer:
X is the GPA
Y is the Salary
Standard deviation of X is 0.4
Standard deviation of Y is 8500
E(X)=2.9
E(Y)=47200
We are given that The correlation between the two variables was r = 0.72
a)


So, slope = 15300
Intercept = 2830
So, equation : 
b) Your brother just graduated from that college with a GPA of 3.30. He tells you that based on this model the residual for his pay is -$1880. What salary is he earning?

Observed salary = Residual + predicted = -1860+53320 = 51440
c)) What proportion of the variation in salaries is explained by variation in GPA?
The proportion of the variation in salaries is explained by variation in GPA = 
As a fraction it is 466666/1000000
The slope formula is y2-y1/x2-x1 so 5-(-1) =6 Then. 1-(-1)=2 so 6/2. =3. THE ANSWER IS 3