TRUE/FALSE: Mark the answers by highlighting T if the statement is true or F if the statement is false.
T F Q2:John Cortiz is examining the results of a study that covered the entire population. John is examining a census.
T F Q3:If the population distribution is skewed left, the mean will be less than the median, and if the population distribution is skewed right, the mean will exceed the median.
T F Q4:When two events are mutually exclusive, the probability that either event will occur can be found by simply multiplying together their individual probabilities of occurrence.
(Questions 11 to 25 are 1/2 point each)
MULTIPLE CHOICE: Select the correct answer in each of Questions 11 to 25 by highlighting your choice. There is only one correct answer to each question. Multiple selection will be taken as an incorrect answer.
Q11: Populations are studied using samples because of all of the following reasons except
a. it usually takes too much time to study the entire population.
b. management need not be concerned about sampling error.
c. studying the entire population is not cost effective.
d. it may not be possible to identify all the members of the population.
Q12: Which of the following are factors that are important in determining the size of the sample needed in a study?
1. The amount of variation in the population
2. The size of the population
3. The amount of error that can be tolerated
d. 1, 2, and 3
Q13: Arrange the following steps in correct sequence:
1. Begin sampling.
2. Determine the sample size.
3. Establish the sampling frame.
a. 1, 2, 3
b. 2, 1, 3
c. 3, 1, 2
d. 3, 2, 1
Q14: Consider the following two columns that describe different types of data:
1. Qualitative B. Discrete
2. Quantitative C. Ordinal
The correctly paired groupings of the two columns is
a. 1-AB 2-CD
b. 1-AD 2-BC
c. 1-AC 2-BD
d. 1-BC 2-AD
d. the standard deviation of the original distribution.
4. the number of rainy days in a month
c. 4 continuous; 1, 2, 3 discrete
d. none of the above
Q20:Given a two-tail test for the population mean, the null hypothesis contains a(n) __________ sign, and the alternative hypothesis contains a(n) ___________ sign.
a. ¹, =
b. =, ³
c. £, =
d. =, ¹
Q21: The appropriate alternative hypothesis for a lower tail test to determine if mean body weight of all the men who have joined a health club is less than 185 pounds would be
a. HA: m ³ 185 lb.
b. HA: m < 185 lb.
c. HA: m = 185 lb.
d. HA: m ¹ 185 lb.
Q22: Which of the following is/are an appropriate null hypothesis for a two-sided test of the difference between two population means?
1. H0: m1 = m2
2. H0: m1 ¹ m2
3. H0: m1 - m2 = 0
d. both 1 and 3
Q23: If the two samples are not independent, their population means can still be compared using the ____________ statistic.
a. paired t
Q24: A linear regression between Y and X produced the following equation for the least squares line:
= -4.3 + 2.1x
Which of the following statements concerning this relationship is true?
a. For every one-unit increase in X, Y increases 4.3 units.
b. For every one-unit increase in X, Y decreases 2.1 units.
c. For every one-unit increase in X, Y decreases 4.3 units.
d. For every one-unit increase in X, Y increases 2.1 units.
Q25: A regression line has been found and the statistician wants to know if the line has a slope. What is the appropriate null hypothesis to test?
a. H0: b1 = 0.
b. H0: b1 > 0.
c. H0: b1 < 0.
d. H0: b1 ¹ 0.