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Question 1
In a cross tabulation
Answer
both variables must be categorical
both variables must be quantitative
one variable must be categorical and the other must be quantitative
either or both variables can be categorical or quantitative
Question 2
In order to test the hypotheses H0: m ? 100 and Ha: m > 100 at an a level of significance, the null hypothesis will be rejected if the test statistic z is
Answer
? za

5
H0: m > 5 Ha: m £ 5
H0: m ³ 5 Ha: m < 5
Question 13
If the data distribution is symmetric, the skewness is
Answer
0
.5
1
None of the other answers is correct.
Question 14
Exhibit 10-5
The following information was obtained from matched samples.
Individual Method 1 Method 2
1 7 5
2 5 9
3 6 8
4 7 7
5 5 6
Refer to Exhibit 10-5. The 95% confidence interval for the difference between the two population means is
Answer
-3.776 to 1.776
-2.776 to 2.776
-1.776 to 2.776
0 to 3.776
Question 15
Exhibit 2-1
The numbers of hours worked (per week) by 400 statistics students are shown below.
Number of hours Frequency
0 - 9 20
10 - 19 80
20 - 29 200
30 - 39 100
Refer to Exhibit 2-1. The percentage of students who work at least 10 hours per week is
Answer
50%
5%
95%
100%
Question 16
Exhibit 10-5
The following information was obtained from matched samples.
Individual Method 1 Method 2
1 7 5
2 5 9
3 6 8
4 7 7
5 5 6
Refer to Exhibit 10-5. If the null hypothesis is tested at the 5% level, the null hypothesis
Answer
should be rejected
should not be rejected
should be revised
None of these alternatives is correct.
Question 17
In a sample of 800 students in a university, 160, or 20%, are Business majors. Based on the above information, the school's paper reported that "20% of all the students at the university are Business majors." This report is an example of
Answer
a sample
a population
statistical inference
descriptive statistics
Question 18
The function that defines the probability distribution of any continuous random variable is a
Answer
normal function
uniform function
Both the normal function and the uniform function are correct.
probability density function
Question 19
Excel provides functions for computing the
Answer
mean
median
mode
Excel provides functions for all of these.
Question 20
The basis for using a normal probability distribution to approximate the sampling distribution of and is
Answer
Chebyshev’s theorem
the empirical rule
the central limit theorem
Bayes’ theorem
Question 21
A measure of the average value of a random variable is called a(n)
Answer
variance
standard deviation
expected value
None of the answers is correct.
Question 22
After the data has been arranged from smallest value to largest value, the value in the middle is called the
Answer
range
median
mean
None of the other answers are correct.
Question 23
Exhibit 2-1
The numbers of hours worked (per week) by 400 statistics students are shown below.
Number of hours Frequency
0 - 9 20
10 - 19 80
20 - 29 200
30 - 39 100
Refer to Exhibit 2-1. The number of students working 19 hours or less
Answer
is 80
is 100
is 180
is 300
Question 24
When the data have the properties of ordinal data and the interval between observations is expressed in terms of a fixed unit of measure, the variable has which scale of measurement?
Answer
nominal
ordinal
interval
ratio
Question 25
Exhibit 2-1
The numbers of hours worked (per week) by 400 statistics students are shown below.
Number of hours Frequency
0 - 9 20
10 - 19 80
20 - 29 200
30 - 39 100
Refer to Exhibit 2-1. The percentage of students working 10 - 19 hours is
Answer
20%
25%
75%
80%
Question 26
A researcher is gathering data from four geographical areas designated: South = 1; North = 2; East = 3; West = 4. The designated geographical regions represent
Answer
categorical data
quantitative data
directional data
either quantitative or categorical data
Question 27
In hypothesis testing, the critical value is
Answer
a number that establishes the boundary of the rejection region
the probability of a Type I error
the probability of a Type II error
the same as the p-value
Question 28
A regression analysis between sales (in $1000) and price (in dollars) resulted in the following equation
= 50,000 - 8x
The above equation implies that an
Answer
increase of $1 in price is associated with a decrease of $8 in sales
increase of $8 in price is associated with an increase of $8,000 in sales
increase of $1 in price is associated with a decrease of $42,000 in sales
increase of $1 in price is associated with a decrease of $8000 in sales
Question 29
The standard deviation is the
Answer
variance squared
square root of the sum of the deviations from the mean
same as the expected value
positive square root of the variance
Question 30
From a population of 200 elements, the standard deviation is known to be 14. A sample of 49 elements is selected. It is determined that the sample mean is 56. The standard error of the mean is
Answer
3
2
greater than 2
less than 2
Question 31
For any continuous random variable, the probability that the random variable takes on exactly a specific value is
Answer
1.00
0.50
any value between 0 to 1
zero
Question 32
The control limits for an np chart are how many standard deviations above and below the expected number of defectives?
Answer
one
two
three
four
Question 33
Excel's NORMSINV function can be used to compute
Answer
cumulative probabilities for a standard normal z value
the standard normal z value given a cumulative probability
cumulative probabilities for a normally distributed x value
the normally distributed x value given a cumulative probability
Question 34
A control chart that is used to monitor the range of the measurements in a sample is
Answer
a p chart
an x-bar chart
an R chart
an np chart
Question 35
A population consists of 500 elements. We want to draw a simple random sample of 50 elements from this population. On the first selection, the probability of an element being selected is
Answer
0.100
0.010
0.001
0.002
Question 36
The expression used to compute an interval estimate of m may depend on any of the following factors except
Answer
the sample size
whether the population standard deviation is known
whether the population has an approximately normal distribution
whether there is sampling error
Question 37
Exhibit 10-10
A local department store is studying the shopping habits of its customers. They think that the longer customers spend in the store the more they buy. Their study resulted in the following information regarding the amount of time women and men spent in a store.
Women Men
Mean 6 minutes 12 seconds 5 minutes 46 seconds
Population Standard deviation 4 seconds 5 seconds
Sample size 32 50
Refer to Exhibit 10-10. At 95% confidence, what is the conclusion for this study?
Answer
There is a significant difference in the time spent in the store between men and women.
There is no significant difference in the time spent in the store between men and women.
It is impossible to make a decision on the basis of the information given.
The sample sizes must be equal in order to answer this question.
Question 38
Independent simple random samples are taken to test the difference between the means of two populations whose variances are not known. The sample sizes are n1 = 32 and n2 = 40. The correct distribution to use is the
Answer
binomial distribution
t distribution with 72 degrees of freedom
t distribution with 71 degrees of freedom
t distribution with 70 degrees of freedom
Question 39
Excel's __________ function can be used to compute the sample correlation coefficient.
Answer
MAX
COVAR
VAR
CORREL
Question 40
Which of the following is an example of quantitative data?
Answer
the player’s number on a baseball uniform
the serial number on a one-dollar bill
the part number of an inventory item
the number of people in a waiting line