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Construct a relative frequency marginal distribution for the given contingency t

ID: 3218085 • Letter: C

Question

Construct a relative frequency marginal distribution for the given contingency table. Round valuese to the nearest thousandth.

x1

x2

x3

y1

20

25

10

y2

40

35

35

Construct a conditional distribution by x for the given contingency table. Round valuese to the nearest thousandth.

x1

x2

x3

y1

30

40

20

y2

50

65

65

The managers of a corporation were surveyed to determine the background that leads to a successful manager. Each manager was rated as being either a good, fair, or poor manager by his/her boss. The manager's educational background was also noted. The data appear below. Given that a manager is only a fair manager, what is the probability that this manager has no college background? Educational Background

manager rating

H.S Degree

Some College

College Degree

Master's or Ph.D

Total

Good Fair Poor

1

5

24

3

39

9

13

45

20

87

6

2

4

22

34

Totals

22

20

73

45

160

4) If one card is drawn from a standard 52 card playing deck, determine the probability of getting a jack, a three, a club or a diamond. Round to the nearest hundredth.

5) At Bill's community college, 49.2% of students are Caucasian and 4.1% of students are Caucasian math majors. What percentage of Caucasian students are math majors?

x1

x2

x3

y1

20

25

10

y2

40

35

35

Explanation / Answer

Construct a relative frequency marginal distribution for the given contingency table

Marginal distribution of X and Y is,

f(x) = f(x,y) summation over y

f(y) = f(x,y) summation over x

Relative frequency is defined as,

relative frequency = count / total count

Marginal distribution of X is,

Marginal distribution of Y is,

The managers of a corporation were surveyed to determine the background that leads to a successful manager. Each manager was rated as being either a good, fair, or poor manager by his/her boss. The manager's educational background was also noted. The data appear below. Given that a manager is only a fair manager, what is the probability that this manager has no college background?

Here we have to find P(no college degree / fair manager) .

P(no college degree / fair manager) = P(no college degree and fair manager) / P(fair manager)

P(no college degree / fair manager) = 9/160

P(fair manager) = 87/160

P(no college degree / fair manager) = (9/160) / (87/160)

= 9/87

4) If one card is drawn from a standard 52 card playing deck, determine the probability of getting a jack, a three, a club or a diamond.

P(getiing a jack, a three, a club or a diamond) =

By using generalization of addition theorem,

P(getiing a jack, a three, a club or a diamond) = P(a jack) + P(a three) + P(a club) + P(a diamond)

There are 4 jacks, 4 three's, 13 clubs, and 13 diamonds in the standard deck.

P(getiing a jack, a three, a club or a diamond) = 4/52 + 4/52 + 13/52 + 13/52

= 34/52

5) At Bill's community college, 49.2% of students are Caucasian and 4.1% of students are Caucasian math majors. What percentage of Caucasian students are math majors?

Here we have given that,

P( Caucasian) = 49.2% = 0.492

P( Caucasian math majors) = 4.1% = 0.041

And we have to find P(math majors).

Here math major and Caucasian are independent event.

So the definition of independent event is,

If A and B are two events then they are said to be independent iff P(A and B) = P(A) * P(B)

Here we use same definition.

P(Caucasian math majors) = P(Caucasian) * P(math majors)

0.041 = 0.492 * P(math majors)

P(math major) = 0.041/0.492 = 0.0833 = 8.3%

x1 x2 x3 total y1 20 25 10 55 y2 40 35 35 110 total 60 60 45 165