QNT 351 FINAL EXAM NEW APRIL 2016 VERSION
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QNT 351 FINAL EXAM NEW APRIL 2016 VERSION
QNT 351 FINAL EXAM NEW APRIL 2016 VERSION
QNT 351 FINAL EXAM NEW APRIL 2016 VERSION
QNT 351 FINAL EXAM
NEW APRIL 2016 VERSION
A time series trend equation for Hammer Hardware is Y’ = 5.6 + 1.2t,
where sales are in millions of dollars and t increases by one unit for each
year. If the value of sales in the base year of 2016 is $5.6 million, what
would be the estimated sales amount for 2018?
$8 million
$6.8 million
Unable to determine from given information
$5.6 million
A weight-loss company wants to statistically prove that its
methods work. They randomly selected 10 clients who had been on the weight loss
program for between 55 and 65 days. They looked at their beginning weights and
their current weight. The statistical test they should utilize is:
t test for difference in paired samples
z test for two population proportions
z test for two population means
t test for two population means
QNT 351 FINAL EXAM NEW APRIL 2016 VERSION
An auditor for American Health Insurance reports that 20% of
policyholders submit a claim during the year. 15 policyholders are selected
randomly. What is the probability that at least 3 of them submitted a claim the
previous year?
.200
.708
.250
.602
A research firm conducted a survey to determine the mean amount
steady smokers spend on cigarettes during a week. A sample of 64 smokers
revealed that = $20 and S = $5. What is the 95% confidence
interval for μ?
$18.78 to $21.23
18.16 to 21.84
$18.60 to $21.40
18.37 to 21.63
QNT 351 FINAL EXAM NEW APRIL 2016
VERSION
When a class interval is expressed as 100 up to 200,
_________________________.
Observations with values of 200 are included in the class
Observations with values of 200 are excluded from the class
Observations with values of 100 are excluded from the class
The class interval is 99
A group of women tried five brands of fingernail polish and
ranked them according to preference. What level of measurement is this?
Ordinal
Nominal
Interval
Ratio
A coffee manufacturer is interested in whether the mean daily
consumption of regular-coffee drinkers is less than that of
decaffeinated-coffee drinkers. A random sample of 50
regular-coffee drinkers showed a mean of 4.35 cups per day, with a standard
deviation of 1.2 cups per day. A sample of 40 decaffeinated coffee
drinkers showed a mean of 5.84 cups per day, with a standard deviation of 1.36
cups per day. What is your computed z-statistic?
z = -2.45
z = -5.44
z = -1.81
z = – 3.90
A hypothesis regarding the weight of newborn infants at a
community hospital is that the mean is 6.6 pounds. A sample of seven infants is
randomly selected and their weights at birth are recorded as 9.0, 7.3, 6.0,
8.8, 6.8, 8.4, and 6.6 pounds. What is the alternate hypothesis?
H1: µ ≠ 6.6
H1: µ ≥ 6.6
H1: µ > 7.6
H1: µ = 6.6
As the size of the sample increases, what happens to the shape
of the distribution of sample means?
It approaches a normal distribution.
It cannot be predicted in advance.
It is positively skewed.
It is negatively skewed.
You perform a hypothesis test at the .05 level of
significance. Your computed p-value turns out to .042. What is your
decision about the hypothesis?
You would reject Ho
You would accept Ho
You would accept Ho if it is a two-tailed test, but reject Ho if
a one-tailed test
You can’t render a decision unless you know the computed test
statistic
University officials say that at least 70% of the voting student
population supports a fee increase. If the 95% confidence interval estimating
the proportion of students supporting the fee increase is [0.75, 0.85], what
conclusion can be drawn?
Since this was not based on the population, no conclusion can be
drawn.
Seventy percent is not in the interval, so assume it will not be
supported.
The interval estimate is above 70%, so infer that it will be
supported.
Seventy percent is not in the interval, so another sample is
needed.
The mean of a normal distribution is 400 pounds. The standard
deviation is 10 pounds. What is the probability of a weight between 415 pounds
and the mean of 400 pounds?
0.3413
0.5000
0.4332
0.1932
The MacBurger restaurant chain claims that the waiting time of
customers for service is normally distributed, with a mean of 3 minutes and a
standard deviation of 1 minute. The quality-assurance department found in
a sample of 50 customers at the Warren Road MacBurger that the mean waiting
time was 2.75 minutes. When you perform a test of hypothesis, what would
be the resulting p-value?
.0586
.0384
.0471
.0512
The tread life of tires mounted on light-duty trucks follows the
normal probability distribution with a mean of 60,000 miles and a standard
deviation of 4,000 miles. Suppose you bought a set of four tires, what is the
likelihood the mean tire life of these four tires is between 57,000 and 63,000
miles?
1.00
Very likely
0.4332
0.8664
In a distribution, the second quartile corresponds with the
__________.
Variance
Mode
Median
Mean
A group of 100 students was surveyed about their interest in a
new International Studies program. Interest was measured in terms of high,
medium, or low. In the study, 30 students responded high interest, 40 students
responded medium interest, and 30 students responded low interest. What is the
relative frequency of students with high interest?
.40
.30
.030
.50
The Director of Golf for a local course wants to study the
number of rounds played by members on weekdays. He gathered the sample
information shown below for 520 rounds. At the .05 significance level, is
there a difference in the number of rounds played by day of the week?
|
Day
|
Rounds
|
|
Monday
|
124
|
|
Tuesday
|
74
|
|
Wednesday
|
104
|
|
Thursday
|
98
|
|
Friday
|
120
|
No, because χ2 = 11.793
Yes, because χ2 = 15.308
No, because χ2 = 7.715
Yes, because χ2 = 12.288
Which approach to probability assumes that the events are
equally likely?
Empirical
Mutually exclusive
Classical
Subjective
Sales at a fast-food restaurant average $6000 per day. The
restaurant decided to introduce an advertising campaign to increase daily
sales. To determine the effectiveness of the advertising campaign, a sample of
49 days of sales was taken. It found that the average daily sales were $6,400
per day. From past history, the restaurant knew that its population standard
deviation is about $1,000. The value of the test statistic is _______.
1.96
6,000
6,400
2.8
A study by the National Park Service revealed that 50% of the
vacationers going to the Rocky Mountain region visit Yellowstone Park, 40%
visit the Grand Tetons, and 35% visit both. What is the probability that a
vacationer will visit at least one of these magnificent attractions?
0.35
0.55
0.95
0.05
The ages of all the patients in the isolation ward of the
hospital are 38, 26, 13, 41, and 22. What is the population standard
deviation?
6.92
10.33
15.85
9.26
The distribution of a sample of the outside diameters of PVC
pipes approximates a symmetrical, bell-shaped distribution. The arithmetic mean
is 14.0 inches, and the standard deviation is 0.1 inches. About 68% of the
outside diameters lie between what two amounts?
13.5 and 14.5 inches
13.9 and 14.1 inches
13.0 and 15.0 inches
13.8 and 14.2 inches
Each month the National Association of Purchasing Managers
publishes the NAPM index. One of the questions asked on the survey to
purchasing agents is: Do you think that the economy is expanding? Last
month, of the 300 responses, 160 answered “yes” to the question. This
month, 170 of the 290 responses indicated that the economy is expanding.
If you’re testing to find if a larger proportion of agents believe that the
economy is expanding this month, what is your computed test statistic?
z = -1.29
t = -1.25
t = -1.07
z = -1.11
The first card selected from a standard 52-card deck was a king.
If it is returned to the deck, what is the probability that a king will be
drawn on the second selection?
1/3 or 0.33
1/13 or 0.077
1/4 or 0.25
12/13 or 0.923
What is the range of values for a coefficient of
correlation?
Unlimited range
0 to +1.0
-1.0 to +1.0 inclusive
-3 to +3 inclusive
Consider the following regression analysis between sales (Y in
$1000) and social media advertising (X in dollars). = 55,000 + 7X
The regression equation implies that an:
increase of $1 in advertising is associated with an increase of
$7,000 in sales.
increase of $1 in advertising is associated with an increase of
$62,000 in sales.
increase of $7 in advertising is associated with an increase of
$7,000 in sales.
increase of $1 in advertising is associated with an increase of
$7 in sales.
When statisticians analyze sample data in order to draw
conclusions about the characteristics of a population, this is referred to
as:
Descriptive statistics
Data summarization
Statistical inference
Data analysis
What is the median of 26, 30, 24, 32, 32, 31, 27, and 29?
32
29.5
30
29
An example of a qualitative variable is _________________.
Weight of a person
Miles between oil changes
Number of children in a family
Color of ink in a pen
Which of the following is true regarding the normal distribution?
It has two
modes.
The points of
the curve meet the x-axis at z = -3 and z = 3.
It is
asymmetrical.
The mean,
median, and mode are all equal.
