# Ans Doc144Y

Question 1
A researcher wants to study the spending habits of customers of a local shopping mall. The mall manager claims that the average spending per customer is \$70, but the researcher believes that the average is less than \$70. A simple random sample of 350 shoppers is obtained. The sample average is \$65 and the sample SD is \$27. We should _________ the null hypothesis.
Reject
Accept
Question 2
A researcher wants to study the spending habits of customers of a local shopping mall. The mall manager claims that the average spending per customer is \$70, but the researcher believes that the average is less than \$70. A simple random sample of 350 shoppers is obtained. The sample average is \$65 and the sample SD is \$27. Should we believe the mall manager’s claim?
No
Yes
A utility company serves 50,000 households. As part of a survey of customer attitudes, they take a simple random sample of 800 of these households. The average number of television sets in the sample households turns out to be 2.56, and the SD is 0.73. What is the observed value for the average number of television sets per household?
1.86
1.50
2.56
3.11
0.03
Question 4
In a month, the Current Population Survey sample amounted to 100,000 people. Of them, 62,000 were employed, and 3,000 were unemployed. True or False: 65% of the sample was in the labor force.
True
False
Question 5
In a certain city, there are 100,000 persons age 18 to 24. A simple random sample of 500 such persons is drawn, of whom 198 turn out to be currently enrolled in college. Estimate the percentage of all persons age 18 to 24 in that city who are currently enrolled in college.
40%
41.1%
38.8%
39.2%
39.6%
Question 6
In a certain city, there are 100,000 persons age 18 to 24. A simple random sample of 500 such persons is drawn, of whom 198 turn out to be currently enrolled in college. Find the SE% for the percentage of all persons age 18 to 24 in that city who are currently enrolled in college.
10.94%
6.88%
1.20%
2.19%
2.22%
Question 7
In a certain city, there are 100,000 persons age 18 to 24. A simple random sample of 500 such persons is drawn, of whom 198 turn out to be currently enrolled in college. If possible, find a 95% confidence interval for the percentage of all persons age 18 to 24 in that city who are currently enrolled in college.
36.72% to 45.48%
not possible
33.06% to 40.41%
none of these
35.22% to 43.98%
Question 8
If 600 different polling firms each construct a 99% confidence interval (based on 600 different random samples) for the average age of male college students in the U.S. majoring in mathematics, how many of these intervals would you expect “on the average” to cover the true average age of such students?
all of them
none of them
580
594
599
Question 9
Given: A box contains a large number of red and blue marbles, but the proportions are unknown. 100 marbles are drawn at random, and 49 turn out to be red. The SE% turns out to be 5%. True or False: The 95% confidence interval for the percentage of red marbles in the sample is 39% to 59%.
False
True
Question 10
Given: A box contains a large number of red and blue marbles, but the proportions are unknown. 100 marbles are drawn at random, and 49 turn out to be red. The SE% turns out to be 5%. True or False: The percentage of red marbles in the box can be estimated as 49%; the SE% is 5%.
True
False
Question 11
When the sample is only a small part of the population, the number of individuals in the population has almost no influence on the accuracy of the sample percentage.
True
False
Question 12
In a month, the Current Population Survey sample amounted to 100,000 people. Of them, 62,000 were employed, and 3,000 were unemployed. True or False: The Bureau would estimate the total number unemployed in the population by using weights obtained by dividing the sample into groups by age, sex, race, area of residence, and so on.
True
False
Question 13
In a month, the Current Population Survey sample amounted to 100,000 people. Of them, 62,000 were employed, and 3,000 were unemployed. True or False: The Bureau would estimate the percentage of the population who are unemployed as 4.62%.
False
True
Question 14
One need not compare the sample size to the population size as far as accuracy is percentages, as long as the sample is a small portion of the population.
True
False
Question 15
The Current Population Survey is a probability sample since it is a multistage cluster sample.
False
True
Question 16
The civilian labor force consists of:
everybody in the US who are either employed or unemployed
civilians who are employed, unemployed, or outside the labor force.
civilians who are either employed or unemployed
none of these
Question 17
The p-value of a test depends on the sample size.
False
True
Question 18
We took a sample from a population of gophers. The proportion of gophers in our sample who had brown fur was 0.55 with a standard error of 0.10. What is the lower limit of the 95% confidence interval for the proportion of gophers with brown fur?
0.75
0.35
0.40
0.445
0.45
Question 19
A researcher wants to study the spending habits of customers of a local shopping mall. The mall manager claims that the average spending per customer is \$70, but the researcher believes that the average is less than \$70. A simple random sample of 350 shoppers is obtained. The sample average is \$65 and the sample SD is \$27. Find the alternative hypothesis.
the population average is greater than \$70
none of these
the population average is less than \$70
the sample average is less than \$70
the population average is \$70
Question 20
A researcher wants to study the spending habits of customers of a local shopping mall. The mall manager claims that the average spending per customer is \$70, but the researcher believes that the average is less than \$70. A simple random sample of 350 shoppers is obtained. The sample average is \$65 and the sample SD is \$27. Find the null hypothesis.
the sample average is less than \$70
the population average is \$70
none of these
the population average is greater than \$70
the population average is less than \$70
Question 21
A researcher wants to study the spending habits of customers of a local shopping mall. The mall manager claims that the average spending per customer is \$70, but the researcher believes that the average is less than \$70. A simple random sample of 350 shoppers is obtained. The sample average is \$65 and the sample SD is \$27. Find the SE for the sample average.
1.34
1.44
5.08
2.91
1.27
Question 22
A researcher wants to study the spending habits of customers of a local shopping mall. The mall manager claims that the average spending per customer is \$70, but the researcher believes that the average is less than \$70. A simple random sample of 350 shoppers is obtained. The sample average is \$65 and the sample SD is \$27. Find the value of the test statistic.
-3.47
-2.36
-0.14
3.45
-2.08
Question 23
A researcher wants to study the spending habits of customers of a local shopping mall. The mall manager claims that the average spending per customer is \$70, but the researcher believes that the average is less than \$70. A simple random sample of 350 shoppers is obtained. The sample average is \$65 and the sample SD is \$27. Find the p-value.
1.90%
0.028%
1.79%
3.57%
25%