Hrm/531 Week 3 Quiz
1. A sample of 20 employee’s salaries from a large company results in the following salaries (in thousands of dollars) for this year.
28 31 34 35 37 47 42 42 49 41 42 60 52 52 51 72 67 61 75 77.
What is the interquartile range (in thousands) of this data set?
(A) 21.5 (B) 10 (C) 50 (D) 23 (E) correct answer is not given
2. Please refer to the previous question.
Suppose each employee in the company receives $3,000 raise for next year. The interquartile range (IQR) of the salaries will:
(A) be unchanged (B) be multiplied by $3,000
(C) increase by $3,000 (D) decrease by $3,000
3. An HIV test has a 9% chance of indicating a false positive and 0.5% chance of indicating a false negative. This test is administered to a population of 1000 …show more content…
If a patient is tested positive, what is the probability that he actually is infected?
(A) 0.93 (B) 0.83 (C) 0.063 (D) 0.0587
4. A study shows that employees that begin their work day at 9:00 a.m. vary their times of arrival uniformly from 8:40 a.m. to 9:30 a.m. The probability that a randomly chosen employee reports to work between 9:00 and 9:10 is:
(A) 40% (B) 20% (C)10% (D) 30% (E)16.7%
5. If A and B are events such that P(A) = 0.20, P(B) = 0.40. Assuming that A and B are independent, what is the probability that none of these two events occur?
(A) 0.40 (B) 0.60 (C) 0.52 (D) 0.48
6. Suppose that the wages of workers for a given company are normally distributed with a mean of $15 per hour. When we consider the proportion of the workers earning more than $13 per hour, we see that:
(A) it is less than the proportion earning less than $13 per …show more content…
(A) Binomial, Normal
(B) Poisson, Exponential
(C) Normal, Binomial
(D) Exponential, Poisson
(E) Binomial, Poisson
14. Which of the following statements are true?
(I) Mutually exclusive events are always independent.
(II) Dependent events are always mutually exclusive.
(III) For two dependent events A and B, P(A∩B)=P(A)P(B|A)
(A) Only (I) is correct.
(B) Only (I) and (III) are correct.
(C) Only (III) is correct.
(D) Only (II) and (III) are correct.
15. The cashier service time at a local bank has an exponential distribution with a mean of 2.5 minutes. What is the probability that the service time is between 2 and 4 minutes? (A) 0.2488 (B) 0.4493 (C) 0.2019 (D) 0.2474 (E) 0.1170
16. A random variable X follows an exponential distribution with a standard deviation of
0.5. What is P(X ≥ 0.5)?
(A) 0.6321 (B) 0.5 (C) 0.3679 (D) 0.7788 (E) 0.2212
4
17. You are given the following summary statistics for a sample of 50 observations:
Mean = 37
25th percentile = 36
Minimum = 24
Median = 44
Range = 28
IQR = 12
Are there any outliers in this sample?
(A) Yes, all observations less than 36
(B) No.
(C) Yes, all observations greater than 48.
(D) Yes, all observations less than 44.
(E) Need more
28 31 34 35 37 47 42 42 49 41 42 60 52 52 51 72 67 61 75 77.
What is the interquartile range (in thousands) of this data set?
(A) 21.5 (B) 10 (C) 50 (D) 23 (E) correct answer is not given
2. Please refer to the previous question.
Suppose each employee in the company receives $3,000 raise for next year. The interquartile range (IQR) of the salaries will:
(A) be unchanged (B) be multiplied by $3,000
(C) increase by $3,000 (D) decrease by $3,000
3. An HIV test has a 9% chance of indicating a false positive and 0.5% chance of indicating a false negative. This test is administered to a population of 1000 …show more content…
If a patient is tested positive, what is the probability that he actually is infected?
(A) 0.93 (B) 0.83 (C) 0.063 (D) 0.0587
4. A study shows that employees that begin their work day at 9:00 a.m. vary their times of arrival uniformly from 8:40 a.m. to 9:30 a.m. The probability that a randomly chosen employee reports to work between 9:00 and 9:10 is:
(A) 40% (B) 20% (C)10% (D) 30% (E)16.7%
5. If A and B are events such that P(A) = 0.20, P(B) = 0.40. Assuming that A and B are independent, what is the probability that none of these two events occur?
(A) 0.40 (B) 0.60 (C) 0.52 (D) 0.48
6. Suppose that the wages of workers for a given company are normally distributed with a mean of $15 per hour. When we consider the proportion of the workers earning more than $13 per hour, we see that:
(A) it is less than the proportion earning less than $13 per …show more content…
(A) Binomial, Normal
(B) Poisson, Exponential
(C) Normal, Binomial
(D) Exponential, Poisson
(E) Binomial, Poisson
14. Which of the following statements are true?
(I) Mutually exclusive events are always independent.
(II) Dependent events are always mutually exclusive.
(III) For two dependent events A and B, P(A∩B)=P(A)P(B|A)
(A) Only (I) is correct.
(B) Only (I) and (III) are correct.
(C) Only (III) is correct.
(D) Only (II) and (III) are correct.
15. The cashier service time at a local bank has an exponential distribution with a mean of 2.5 minutes. What is the probability that the service time is between 2 and 4 minutes? (A) 0.2488 (B) 0.4493 (C) 0.2019 (D) 0.2474 (E) 0.1170
16. A random variable X follows an exponential distribution with a standard deviation of
0.5. What is P(X ≥ 0.5)?
(A) 0.6321 (B) 0.5 (C) 0.3679 (D) 0.7788 (E) 0.2212
4
17. You are given the following summary statistics for a sample of 50 observations:
Mean = 37
25th percentile = 36
Minimum = 24
Median = 44
Range = 28
IQR = 12
Are there any outliers in this sample?
(A) Yes, all observations less than 36
(B) No.
(C) Yes, all observations greater than 48.
(D) Yes, all observations less than 44.
(E) Need more