Question

DRIVERS (X ) CARS (Y )

5 4

5 3

2 2

2 2

3 2

1 1

2 2

(a) Construct a scatterplot to verify a lack of pronounced curvilinearity. (already did this part)

(b) Determine the least squares equation for these data. (Remember, you will first have to calculate r, SSy and SSx)

(c) Determine the standard error of estimate, sy|x, given that n = 7.

(d) Predict the number of cars for each of two new families with two and five drivers

please show work thank you so much.  

Answer 1

a) Scatter plot:

b)

Sample size, n =	7
Ʃ x =	20
Ʃ y =	16
Ʃ xy =	54
Ʃ x² =	72
Ʃ y² =	42
x̅ =	2.8571
y̅ =	2.2857
SSxx = Ʃx² - (Ʃx)²/n =	14.8571
SSyy = Ʃy² - (Ʃy)²/n =	5.4286
SSxy = Ʃxy - (Ʃx)(Ʃy)/n =	8.2857
r = SSxy/√(SSxx*SSyy)	0.9226

b = SSxy/SSxx = 8.2857/14.8571 = 0.5577

a = y̅ -b* x̅ =2.2857 - 0.5577*2.8571 = 0.6923

Regression equation:

c) Standard error of estimate =

d) Predicted cars at x=2

Predicted cars at x = 5