The following data relates to the scores obtained by 9 salesmen of a company in an intelligence test and their weekly sales in thousands of Rs. Salesmen:
A
B
C
D
E
F
G
H
I
Test score :
50
60
50
60
80
50
80
40
70
Weekly sales :
30
60
40
50
60
30
70
50
60
Obtain the regression equation of sales on test scores of the salesmen and estimate sales if the test score of a salesman is 65.

y = 0.75x + 5 ;

53.75

Step-by-step explanation:

Giveb the data:

Test score :

50

60

50

60

80

50

80

40

70

Weekly sales :

30

60

40

50

60

30

70

50

60

The linear regression equation model obtained from the online regression equation is :

y = 0.75x + 5 ; where ;

y = weekly sales ; x = test score ; 0.75 = slope / gradient ; 5 = intercept

sales if the test score of a salesman is 65.

y = 0.75x + 5

x = 65

y = 0.75(65) + 5

y = 48.75 + 5

y = 53.75

(1, –1), (16, –4), (36, –6)

step-by-step explanation:

given that the function is

this can also be written as

we have to graph this function and check which list of points lie on the graph

see attachment for graph:

we find that the points lying are (1,-1) (16,-4) and (36,-6)

since square root is there we find that x can only be posiitve but y can be since square root both positive and negative.

let's call the solutions x₁ = (5 - 2√7)/3 and x₂ = (5 + 2√7)/3

then the equation is (x-x₁)(x-x₂) = 0

if you fill that in you get a lot of numbers which you can recognize as ax²+bx+c=0.

step-by-step explanation:

you can see that a=1 (there is just an x²)

b = (-5 -2√7 + 2√7 - 5)/3 = -10/3

c = -2√7)/3 ) * (-5+2√7)/3) = -1/3

so your answer is 3x^2 – 10x – 1 = 0