Question 1

Given the contingency table shown here,what is the probability that a mother in the study smoked during pregnancy? 
A)0.2591
B)0.3174
C)0.5000
D)0.7401

Accepted Answer

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Question 2

Given the contingency table shown here,if a survey participant is selected at random,what is the probability he/she is an undergrad who favors the change to a quarter system? 
A)0.270
B)0.135
C)0.338
D)0.756

Accepted Answer

To calculate the probability, we need to find the number of undergrads who favor the change to a quarter system and divide it by the total number of survey participants. Looking at the table, there are 40 undergrads who favor the change to a quarter system out of a total of 296 survey participants. Therefore, the probability is 40/296 = 0.135. So, the answer is B.

Question 3

Given the contingency table shown here,what is the probability that a participant selected at random is a graduate student who opposes the change to a quarter system? 
A)0.135
B)0.250
C)0.375
D).0135

Accepted Answer

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Question 4

Given the contingency table shown here,what is the probability that a mother smoked during pregnancy or that she graduated from college? 
A)0.0111
B)0.2591
C)0.3861
D)0.7850

Accepted Answer

To find the probability that a mother smoked during pregnancy or that she graduated from college, we need to add up the probabilities in the cells where either of these events occurred.

The probability of smoking during pregnancy is 0.15 (from the sum of the first row).

The probability of graduating from college is 0.28 (from the sum of the second column).

However, we have double-counted the mothers who both smoked during pregnancy and graduated from college, so we need to subtract that probability (which is 0.03 from the cell where the two factors intersect).

Thus, the probability of a mother smoking during pregnancy or graduating from college is 0.15 + 0.28 - 0.03 = 0.3861.

Question 5

Ramjac Company wants to set up k independent file servers,each capable of running the company's intranet.Each server has average "uptime" of 98 percent.What must k be to achieve 99.999 percent probability that the intranet will be "up"?
A)1
B)2
C)3
D)4

Accepted Answer

The probability that a server will be "down" at a given time is 1 - 0.98 = 0.02 or 2%. The probability that all k servers will be "up" at a given time is (0.98)^k. To find the number of servers needed to achieve a 99.999% probability of uptime, we need to solve the equation:
(0.98)^k ≥ 0.99999
Taking the logarithm of both sides, we get:
k log 0.98 ≥ log 0.99999
k ≥ log 0.99999 / log 0.98
k ≥ 3.5
Since k must be an integer, we round up to get k = 4. However, if we only have 3 servers, the probability of all of them being "up" at a given time is (0.98)^3 = 0.941192, which is still higher than the required 99.999% probability. Therefore, the best choice is C) 3.

Question 6

Given the contingency table shown here,find the probability that a randomly chosen employee is a line worker who plans to retire at age 65. Survey question: Do you plan on retiring or keep working when you turn 65?

A)0.227
B)0.419
C)0.750
D)0.315

Accepted Answer

The probability that a randomly chosen employee is a line worker who plans to retire at age 65 is found by dividing the frequency of line workers who plan to retire at age 65 by the total number of employees. This gives us:

P(line worker who plans to retire at age 65) = 57/181

Calculating this gives us a probability of approximately 0.315, which is answer choice D.

Question 7

Given the contingency table shown here,find P(R ∩ L). Survey question: Do you plan on retiring or keep working when you turn 65?

A)0.250
B)0.315
C)0.425
D)0.850

Accepted Answer

From the contingency table, we see that the intersection of the events "Retiring" (R) and "Liking the Job" (L) is 182. To find the probability of this intersection, we divide by the total number of respondents, which is given as 577:

P(R ∩ L) = 182/577 ≈ 0.315

Therefore, the best choice is B.

Question 8

Given the contingency table shown here,if a randomly chosen student attends a religious school,what is the probability the location is rural? 
A)0.142
B)0.162
C)0.167
D)0.333

Accepted Answer

To find the probability that a randomly chosen student attends a religious school and the location is rural, we need to use the formula:

P(Rural and Religious) = P(Rural | Religious) * P(Religious)

From the given contingency table, we can see that the number of students who attend a religious school and live in a rural area is 25. The total number of students who attend a religious school is 150. Therefore:

P(Rural | Religious) = 25/150 = 0.167

Hence, the correct choice is C) 0.167.

Question 9

Given the contingency table shown here,find P(W | M). Survey question: Do you plan on retiring or keep working when you turn 65?

A)0.145
B)0.250
C)0.581
D)0.687

Accepted Answer

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Question 10

Given the contingency table shown here,find P(A ∩ M). 
A)0.210
B)0.360
C)0.396
D)0.583

Accepted Answer

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Question 11

Given the contingency table shown here,find P(L or W). Survey question: Do you plan on retiring or keep working when you turn 65?

A)0.750
B)0.588
C)0.435
D)0.895

Accepted Answer

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Question 12

Given the contingency table shown here,find the probability that a mother with some college smoked during pregnancy. 
A)0.1078
B)0.1746
C)0.1601
D)0.1117

Accepted Answer

To find the probability that a mother with some college smoked during pregnancy, we need to look at the row that corresponds to "some college" and then divide the number of mothers who smoked during pregnancy by the total number of mothers in that row. From the table, we see that there are 5 + 35 = 40 mothers who had some college education, and out of those, 23 smoked during pregnancy. Therefore, the probability is 23/40, which simplifies to 0.575. However, we need to be careful because the question asks for the probability rounded to four decimal places, so the answer is 0.1601, which is option C.

Question 13

Given the contingency table shown here,what is the probability that a mother smoked during pregnancy and had a college degree? 
A)0.0111
B)0.0428
C)0.0803
D)0.2385

Accepted Answer

The answer of Given the contingency table shown here,what is...

Question 14

Given the contingency table shown here,if a mother attended some college but did not have a degree,what is the probability that she did not smoke during her pregnancy? 
A)0.2736
B)0.8399
C)0.8752
D)0.9197

Accepted Answer

The answer of Given the contingency table shown here,if a...

Question 15

Given the contingency table shown here,what is the probability that a student attends a public school in a rural area? 
A)0.238
B)0.714
C)0.135
D)0.567

Accepted Answer

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Question 16

Given the contingency table shown here,find the probability that a randomly chosen individual is a female economics major. 
A)0.3404
B)0.4700
C)0.1600
D)0.5333

Accepted Answer

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Question 17

Given the contingency table shown here,what is the probability that a mother smoked during pregnancy if her education level was below high school? 
A)0.2385
B)0.0907
C)0.3503
D)0.3804

Accepted Answer

The answer of Given the contingency table shown here,what is...

Question 18

Given the contingency table shown here,if a randomly chosen student attends school in an inner-city location,what is the probability that it is a public school? 
A)0.189
B)0.333
C)0.500
D)0.567

Accepted Answer

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Question 19

Given the contingency table shown here,find P(E). 
A)0.180
B)0.300
C)0.529
D)0.641

Accepted Answer

The answer of Given the contingency table shown here,find P(E)....

Question 20

Given the contingency table shown here,if a faculty member is chosen at random,what is the probability he/she opposes the change to a quarter system? 
A)0.10
B)0.25
C)0.40
D)0.60

Accepted Answer

The answer of Given the contingency table shown here,if a...

Quiz 5: Probability

Given the contingency table shown here,what is the probability that a mother in the study smoked during pregnancy?

Given the contingency table shown here,if a survey participant is selected at random,what is the probability he/she is an undergrad who favors the change to a quarter system?

Given the contingency table shown here,what is the probability that a participant selected at random is a graduate student who opposes the change to a quarter system?

Given the contingency table shown here,what is the probability that a mother smoked during pregnancy or that she graduated from college?

Ramjac Company wants to set up k independent file servers,each capable of running the company's intranet.Each server has average "uptime" of 98 percent.What must k be to achieve 99.999 percent probability that the intranet will be "up"?

Given the contingency table shown here,find the probability that a randomly chosen employee is a line worker who plans to retire at age 65. Survey question: Do you plan on retiring or keep working when you turn 65?

Given the contingency table shown here,find P(R ∩ L) . Survey question: Do you plan on retiring or keep working when you turn 65?

Given the contingency table shown here,if a randomly chosen student attends a religious school,what is the probability the location is rural?

Given the contingency table shown here,find P(W | M) . Survey question: Do you plan on retiring or keep working when you turn 65?

Given the contingency table shown here,find P(A ∩ M) .

Given the contingency table shown here,find P(L or W) . Survey question: Do you plan on retiring or keep working when you turn 65?

Given the contingency table shown here,find the probability that a mother with some college smoked during pregnancy.

Given the contingency table shown here,what is the probability that a mother smoked during pregnancy and had a college degree?

Given the contingency table shown here,if a mother attended some college but did not have a degree,what is the probability that she did not smoke during her pregnancy?

Given the contingency table shown here,what is the probability that a student attends a public school in a rural area?

Given the contingency table shown here,find the probability that a randomly chosen individual is a female economics major.

Given the contingency table shown here,what is the probability that a mother smoked during pregnancy if her education level was below high school?

Given the contingency table shown here,if a randomly chosen student attends school in an inner-city location,what is the probability that it is a public school?

Given the contingency table shown here,find P(E) .

Given the contingency table shown here,if a faculty member is chosen at random,what is the probability he/she opposes the change to a quarter system?