Question

The chart below shows the results of a sample of 10 workers from a large company.

Employee	Years of Experience	Income (In thousands of dollars)
1	0	20
2	5	30
3	5	40
4	10	30
5	10	50
6	15	50
7	20	60
8	25	50
9	30	70
10	35	60

• What is the equation of the line of best fit? ( Options: y= 1.16+28x, y=28+1.16x, y=1.16-28x, y+28-1.16x)
• What can we expect an employee to make if they have 7 years of experience? _____ (Round to the nearest thousand.)
  • This is an example of extrapolation or interpolation
• The correlation coefficient is _____
• This means there is a (options: weak negative, a weak positive, a strong negative, a strong positive, no relationship) between variables based on the data from the sample.

Answer 1

(1)

Question:

What is the equation of the line of best fit?

Correct option:

y=28+1.16x

Explanation:
From the given data, the following Table is calculated:

X	Y	XY	X2	Y2
0	20	0	0	400
5	30	150	25	900
5	40	200	25	1600
10	30	300	100	900
10	50	500	100	2500
15	50	750	225	2500
20	50	1200	400	3600
25	60	1250	625	2500
30	70	2100	900	4900
35	60	2100	1225	3600
Total = 155	460	8550	3625	23400

So,

the equation of the line of best fit

y=28+1.16x

(2)

Question:

What can we expect an employee to make if they have 7 years of experience?

For x = 7, we get:

y=28+ (1.16 X 7) = 36.12 thousand

So,

Answer is:

36,000

(3)

Question:

This is an example of extrapolation or interpolation

This is an example of interpolation

(4)

Question:

The correlation coefficient is _____

0.8581

Explanation:

(5)

Question:

This means there is a (options: weak negative, a weak positive, a strong negative, a strong positive, no relationship) between variables based on the data from the sample.

This means there is a strong positive relationship between variables based on the data from the sample.