Question

An economist is studying the job market in Denver area neighborhoods. Let x represent the total number of jobs in a given neighborhood, and let y represent the number of entry-level jobs in the same neighborhood. A sample of six Denver neighborhoods gave the following information (units in hundreds of jobs). x 14 31 49 28 50 25 y 1 3 7 5 9 3 Complete parts

(a) through (e), given: Σx = 197,Σy = 28 ,Σx2 = 7467 ,Σy2 = 174 ,Σxy = 1115 and r ≈ 0.941

(b) Verify the given sums Σx, Σy, Σx2, Σy2, Σxy, and the value of the sample correlation coefficient r. (Round your value for r to three decimal places.)

Σx = Σy = Σx2 = Σy2 = Σxy = r =

(c) Find x, and y. Then find the equation of the least-squares line y hat = a + bx. (Round your answers for x and y to two decimal places. Round your answers for a and b to three decimal places.)

x =

y =

y hat= ( )+( )x

(e) Find the value of the coefficient of determination r2. What percentage of the variation in y can be explained by the corresponding variation in x and the least-squares line? What percentage is unexplained? (Round your answer for r2 to three decimal places. Round your answers for the percentages to one decimal place.)

r2 =

explained %=

unexplained %=

(f) For a neighborhood with x = 34 hundred jobs, how many are predicted to be entry level jobs? (Round your answer to two decimal places.)

( )hundred jobs

Answer #1

An economist is studying the job market in Denver area
neighborhoods. Let x represent the total number of jobs in
a given neighborhood, and let y represent the number of
entry-level jobs in the same neighborhood. A sample of six Denver
neighborhoods gave the following information (units in hundreds of
jobs).
x
14
32
49
28
50
25
y
3
2
5
5
9
3
Complete parts (a) through (e), given Σx = 198,
Σy = 27, Σx2 = 7530,...

An economist is studying the job market in Denver area
neighborhoods. Let x represent the total number of jobs in a given
neighborhood, and let y represent the number of entry-level jobs in
the same neighborhood. A sample of six Denver neighborhoods gave
the following information (units in hundreds of jobs). x 18 30 51
28 50 25 y 2 2 6 5 9 3 Complete parts (a) through (e), given Σx =
202, Σy = 27, Σx2 = 7734,...

An economist is studying the job market in Denver area
neighborhoods. Let x represent the total number of jobs in a given
neighborhood, and let y represent the number of entry-level jobs in
the same neighborhood. A sample of six Denver neighborhoods gave
the following information (units in hundreds of jobs). x 13 32 51
28 50 25 y 3 2 7 5 9 3 Complete parts (a) through (e), given Σx =
199, Σy = 29, Σx2 = 7703,...

An economist is studying the job market in Denver area
neighborhoods. Let x represent the total number of jobs in
a given neighborhood, and let y represent the number of
entry-level jobs in the same neighborhood. A sample of six Denver
neighborhoods gave the following information (units in hundreds of
jobs).
x
16
33
53
28
50
25
y
2
3
5
5
9
3
Given: Σx = 205 Σy = 27
Σx2 = 8063
Σy2 =...

An economist is studying the job market in Denver area
neighborhoods. Let x represent the total number of jobs in
a given neighborhood, and let y represent the number of
entry-level jobs in the same neighborhood. A sample of six Denver
neighborhoods gave the following information (units in hundreds of
jobs).
x
18
31
51
28
50
25
y
1
4
7
5
9
3
Complete parts (a) through (e), given Σx = 203,
Σy = 29, Σx2 = 7795,...

Do heavier cars really use more gasoline? Suppose a car is
chosen at random. Let x be the weight of the car (in hundreds of
pounds), and let y be the miles per gallon (mpg).
x
27
43
31
47
23
40
34
52
y
30
20
25
13
29
17
21
14
Complete parts (a) through (d), given Σx = 297, Σy = 169, Σx2 =
11,737, Σy2 = 3861, Σxy = 5845, and r ≈ −0.944.
(a) Verify...

Let x be the age in years of a licensed automobile
driver. Let y be the percentage of all fatal accidents
(for a given age) due to speeding. For example, the first data pair
indicates that 39% of all fatal accidents of 17-year-olds are due
to speeding.
x
17
27
37
47
57
67
77
y
39
22
22
12
10
7
5
Complete parts (a) through (e), given
Σx = 329, Σy = 117,
Σx2 = 18,263,
Σy2 =...

Let x be the age of a licensed driver in years. Let
y be the percentage of all fatal accidents (for a given
age) due to failure to yield the right of way. For example, the
first data pair states that 5% of all fatal accidents of
37-year-olds are due to failure to yield the right of way.
x
37
47
57
67
77
87
y
5
8
10
14
33
46
Complete parts (a) through (e), given Σx =...

Do heavier cars really use more gasoline? Suppose a car is
chosen at random. Let x be the weight of the car (in hundreds of
pounds), and let y be the miles per gallon (mpg). x 30 44 33 47 23
40 34 52 y 33 21 22 13 29 17 21 14 Complete parts (a) through (e),
given Σx = 303, Σy = 170, Σx2 = 12,123, Σy2 = 3950, Σxy = 6040, and
r ≈ −0.853.
(a) Draw...

Do heavier cars really use more gasoline? Suppose a car is
chosen at random. Let x be the weight of the car (in hundreds of
pounds), and let y be the miles per gallon (mpg). x 27 43 29 47 23
40 34 52 y 31 18 27 13 29 17 21 14 Complete parts (a) through (e),
given Σx = 295, Σy = 170, Σx2 = 11,617, Σy2 = 3950, Σxy = 5794, and
r ≈ −0.951. (a) Draw...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 1 minute ago

asked 1 minute ago

asked 1 minute ago

asked 1 minute ago

asked 4 minutes ago

asked 6 minutes ago

asked 6 minutes ago

asked 21 minutes ago

asked 21 minutes ago

asked 22 minutes ago

asked 23 minutes ago

asked 33 minutes ago