Question

The following table summarizes the responses of a sample of 25 workers who were asked how many miles they had to travel to go to work.

Miles	Frequency
0<10	3
10<20	10
20<30	2
30<40	5
40<50	4
50<60	1

Suppose you build a histogram with this information. Describe it

A. "A single peak, skewed to the left (left-skewed)."

B. "A single peak, skewed to the right (right-skewed)."

C. "Bimodal, skewed to the right (right-skewed)."

D. "Bimodal, skewed to the left (left-skewed)."

"The survival time of patients after a certain type of surgery has a skewed distribution to the right due to the presence of outliers. Consequently, which statement is more likely to be correct?"

A. Median (median)> range

B. Average (mean) <median (median)

C. Average (mean)> median (median)

D. None of the above.

A distribution will be skewed to the left (left-skewed) if

A. Median <mid axis (midhinge)

B. Medium> mid axis (midhinge)

C. Median = mid axis (midhinge)

D. None of the above.

"Since P (A) = 0.4, P (B) = 0.5 and P (A ∩B) = 0.05. Then:"

A. P (A∪B) = 0.80; P (A / B) = 0.1

B. P (A∪B) = 0.85; P (A / B) = 0.15

C. P (A∪B) = 0.85; P (A / B) = 0.10

D. None of the above.

The average of the exam of a class of 30 students was 75. The average of the exam for the 20 male students of that class was 70. Then the average of the exam for the 10 female students was:

A. 85

B. 80

C. 75

D. None of the above.

"Two events are complementary (that is, they are complements), yes"

A. The sum of your odds is equal to one.

B. The probability of your interception is equal to one.

C. They are two independent events with equal probabilities.

D. None of the above.

What probability function can be used to describe the number of damaged printers in a random sample of 12 printers taken from a shipment of 70 printers consisting of 6 damaged printers?

A. Poisson

B. Hypergeometric

C. Binomial

D. None of the above.

You have the following probability distribution of the random variable X:

X	P(X)
100	0.1
150	0.2
200	0.3
250	0.3
300	0.1

The expected value of X is:

A. 175

B. 150

C. 205

D. None of the above.

The variable Z has a standard normal distribution. The probability P (0.71 <Z <1.43) is:

A. 0.1625

B. 0.92

C. 0.5

D. 0.485

"Suppose that X has a normal distribution with a mean μ = $ 64. Given that P (X> $ 75) = 0.2981, we can calculate that the standard deviation of X is approximately"

A. $ 20.75

B. $ 13.75

C. $ 5.83

D. $ 7.05

"In Quebec, 90% of the population is Catholic. In a random sample of 8 people find the probability that the sample contains at least five Catholics."

A. 0.005

B. 0.0331

C. 0.995

D. 0.9619

Answer 1

X	P(X)	X*P(X)
100	0.1	10
150	0.2	30
200	0.3	60
250	0.3	75
300	0.1	30
	TOTAL	205

The expected value of X is: =205

C. 205

The variable Z has a standard normal distribution. The probability P (0.71 <Z <1.43) is:

Rcode:

library(tigerstats)
pnormGC(bound=c(0.71 ,1.43),region="between", mean=0,sd=1,graph=TRUE)

The probability P (0.71 <Z <1.43) is:0.1625

MARK OPTION-A

Suppose that X has a normal distribution with a mean μ = $ 64. Given that P (X> $ 75) = 0.2981, we can calculate that the standard deviation of X is approximately

Rcode:

library(tigerstats)

pnormGC(bound=75,region="above",mean=64,sd=20.75,graph=TRUE)

standard deviation=20.75

MARK OPTION A

"In Quebec, 90% of the population is Catholic. In a random sample of 8 people find the probability that the sample contains at least five Catholics

p=0.90

n=8

P(X>=5)

Rcode s

  
library(tigerstats)
pbinomGC(bound=c(5,8),region="between", size=8,prob=0.9,graph=TRUE)

mark option c

0.995