Question

The following are advertised sale prices of color televisions at an electronics store.

Size (inches)	Sale Price ($)
9	137
20	187
27	277
31	447
35	1177
40	2177
60	2497

A. Decide which variable should be the independent variable and which should be the dependent variable.

Independent variable: size; Dependent variable: OR sale price Independent variable: sale price; Dependent variable: size    

B. Draw a scatter plot of the data.

C.

Does it appear from inspection that there is a relationship between the variables? Why or why not?

-Yes, it appears that the television cost increases with television size

-.Yes, it appears that the television cost decreases with television size.  

- No, there is no visible relationship between the variables

D. Calculate the least squares line. Put the equation in the form of:

ŷ = a + bx.

(Round your answers to three decimal places.)
ŷ =

E. Find the correlation coefficient r. (Round your answer to four decimal places.)
r =

Is it significant?

YesNo  

F. Find the estimated sale price for a 33 inch television. (Use your equation from part (d). Round your answer to two decimal places.)
$

Find the estimated sale price for a 51 inch television. (Use your equation from part (d). Round your answer to two decimal places.)
$

G. Does it appear that a line is the best way to fit the data? Why or why not?

H. Are there any outliers in the above data?

I. What is the slope of the least squares (best-fit) line? (Round your answer to three decimal places.)

()
Interpret the slope.

As the size of the television  ---Select--- decreases increases by one inch, the sale price  ---Select--- decreases increases by $

Answer 1

Ans:

	Size (inches)	Sale Price ($)
1	9	137
2	20	187
3	27	277
4	31	447
5	35	1177
6	40	2177
7	60	2497
Average	31.714	985.571
SD	16.101	990.832
r	0.8944
slope,b	55.038
intercept,a	-759.909

a)Independent variable: size; Dependent variable: OR sale price

b)Yes, it appears that the television cost increases with television size

c)y'=-759.909+55.038 x

d)r=0.8944

yes,significant

e)when x=33

y'=-759.909+55.038*33=1056.35

when x=51

y'=-759.909+55.038*51=2047.03

f)

Interpret the slope.

As the size of the television increases by one inch, the sale price increases by $55.038