Course 1131 – QMB3200 – Application of Quantitative Methods in Business – Section
RVC – Spring 2013
Test Final Exam
Started 4/24/13 12:30 PM
Submitted 4/24/13 1:32 PM
Status Completed
Score 92 out of 100 points
Time Elapsed 1 hour, 1 minute out of 2 hours.
Instructions
• Question 1
4 out of 4 points
There are two types of machines called type A and type B. Both type A and type B can be
used to produce a certain product. The production manager wants to compare efficiency of
the two machines. He assigns each of the fifteen workers to both types of machines to
compare the hourly production rate of the 15 workers. In other words, each worker
operates machine A and machine B for one hour each. These two samples are independent.
Answer
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• Question 2
4 out of 4 points
The average waiting time per customer at a fast food restaurant has been 7.5 minutes. The
customer waiting time has a normal distribution. The manager claims that the use of a new
cashier system will decrease the average customer waiting time in the store. Based on a
random sample of 16 customer transactions the mean waiting time is 6.3 minutes and the
standard deviation is 2 minutes per customer. What is the value of the test statistic?
Answer
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• Question 3
4 out of 4 points
In testing the difference between the means of two normally distributed populations using
large independent random samples, the alternative hypothesis indicates no differences
between the two specified means.
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• Question 4
4 out of 4 points
When comparing two independent population means, if n1 = 13 and n2 = 10, degrees of
freedom for the t statistic is 22.
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• Question 5
4 out of 4 points
As the level of significance α increases, we are more likely to reject the null hypothesis.
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• Question 6
4 out of 4 points
The null hypothesis always includes an equal (=) sign.
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• Question 7
4 out of 4 points
When conducting a hypothesis test about a single mean, at a given level of significance, as
the sample size n increases, the power of the test:
Answer
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• Question 8
4 out of 4 points
Which of the following assumptions are necessary in testing the difference between the
means of two normally distributed populations using large independent random samples?
Answer
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• Question 9
4 out of 4 points
If we are testing the hypothesis about the mean of a population of paired differences with
samples of n1 = 10, n2 = 10, the degrees of freedom for the t statistic is ____.
Answer
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• Question 10
4 out of 4 points
A financial analyst believes that a fast food chain should be purchased if average daily
profits are more than $1,000 per day. The standard deviation of daily profits is known to be
$200 and the significance level is .05. A random sample of 100 days resulted in an average
profit of $1050. At the .05 level of significance, there is not sufficient evidence that the
average daily profit is more than $1000 per day.
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• Question 11
0 out of 4 points
When the null hypothesis is not rejected, there is no possibility of making a Type I error.
Answer
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• Question 12
0 out of 4 points
In testing for the equality of means from two independent populations, if the null
hypothesis is false, the test could result in:
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• Question 13
4 out of 4 points
For the following hypothesis test where H0: µ ≤ 10 vs. Ha: µ > 10, we reject H0 at level of
significance α and conclude that the true mean is greater than 10 when the true mean is
really 8. Based on this information we can state that we have:
Answer
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• Question 14
4 out of 4 points
In testing for the equality of means from two independent populations, if the null
hypothesis is rejected, the test could result in:
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• Question 15
4 out of 4 points
In a manufacturing process a random sample of 9 bolts manufactured has a mean length of
3 inches with a standard deviation of .3 inches. What is the 95% confidence interval for the
true mean length of the bolt?
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• Question 16
4 out of 4 points
When comparing two independent population means by using large samples selected from
populations with equal variances, the correct test statistic to use is t.
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• Question 17
4 out of 4 points
For the following hypothesis test where H0: µ ≤ 10 vs. Ha: µ > 10, we reject H0 at level of
significance α and conclude that the true mean is greater than 10 when the true mean is
really 14. Based on this information we can state that we have:
Answer
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• Question 18
4 out of 4 points
The null hypothesis is a statement that will be accepted only if there is convincing sample
evidence that it is true.
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• Question 19
4 out of 4 points
What value(s) of alpha would we reject H0 for µ greater than the mean 10 if µ = 11, s = 2,
and n = 36?
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• Question 20
4 out of 4 points
In a manufacturing process, we are interested in measuring the average length of a certain
type of bolt. Past data indicates that the standard deviation is .25 inches. How many bolts
should be sampled in order to make us 95% confident that the sample mean bolt length is
within .02 inches of the true mean bolt length?
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• Question 21
4 out of 4 points
When comparing two population means based on independent random samples, the pooled
estimate of the variance is used if both population standard deviations are known.
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• Question 22
4 out of 4 points
If a null hypothesis is rejected at a significance level of 0.01, it will ______ be rejected at a
significance level of 0.05
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• Question 23
4 out of 4 points
In order to test the effectiveness of a drug called XZR designed to reduce cholesterol
levels, 9 heart patients cholesterol levels are measured before they are given the drug. The
same 9 patients use XZR for two continuous months. After two months of continuous use
the 9 patients cholesterol levels are measured again. The comparison of cholesterol levels
before vs. after administering the drug is an example of testing the difference between:
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• Question 24
4 out of 4 points
In one-way ANOVA, the treatment sum of squares equals:
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• Question 25
4 out of 4 points
In a manufacturing process a random sample of 9 bolts manufactured has a mean length of
3 inches with a variance of .09. What is the 90% confidence interval for the true mean
length of the bolt?
Answer
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Wednesday, April 24, 2013 2:24:00 PM EDT
User Ramon Grande
Course 1131 – QMB3200 – Application of Quantitative Methods in Business – Section
RVC – Spring 2013
Test Final Exam
Started 4/24/13 1:36 PM
Submitted 4/24/13 2:29 PM
Status Completed
Score 96 out of 100 points
Time Elapsed 53 minutes out of 2 hours.
Instructions
• Question 1
4 out of 4 points
The following list represents a sample of the ages of the soldiers enlisting in the military:
19, 22, 23, 19, 21, 22, 19, 23, 21. Assume that the population standard deviation is known
to be 2 years. Construct a 99% confidence interval for the average age of the soldier
enlisting in the military.
Answer
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• Question 2
4 out of 4 points
Which statement is incorrect?
Answer
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• Question 3
4 out of 4 points
When the null hypothesis is not rejected, there is no possibility of making a Type I error.
Answer
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• Question 4
4 out of 4 points
When conducting a hypothesis test about a single mean, reducing the level of significance
(?) will increase the size of the rejection region.
Answer
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• Question 5
4 out of 4 points
If we are testing the hypothesis about the mean of a population of paired differences with
samples of n1 = 10, n2 = 10, the degrees of freedom for the t statistic is ____.
Answer
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• Question 6
4 out of 4 points
The exact spread of the t-distribution depends on ________.
Answer
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• Question 7
4 out of 4 points
When comparing two independent population means, if n1 = 13 and n2 = 10, degrees of
freedom for the t statistic is 22.
Answer
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• Question 8
4 out of 4 points
If a two-sided null hypothesis is rejected for a single mean at a given significance level, the
corresponding one- sided null hypothesis (i.e., the same sample size, the same standard
deviation, and the same mean) will_________ be rejected at the same significance level.
Answer
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• Question 9
4 out of 4 points
Which of the following assumptions are necessary in testing the difference between the
means of two normally distributed populations using large independent random samples?
Answer
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• Question 10
4 out of 4 points
What sample size would be required to estimate µ to within ± 3 with 95% confidence if the
population standard deviation is 24.5?
Answer
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• Question 11
4 out of 4 points
Given the following information, calculate the degrees of freedom that should be used in
the pooled-variance t test.
s12 = 4 s22 = 6 n1 = 16 n2 = 25
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• Question 12
4 out of 4 points
Type II error is defined as the probability of ________________ H0 , when it should
___________.
Answer
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• Question 13
4 out of 4 points
In testing the difference between the means of two normally distributed populations using
large independent random samples, the alternative hypothesis indicates no differences
between the two specified means.
Answer
Selected Answer:
• Question 14
4 out of 4 points
The null hypothesis is a statement that will be accepted only if there is convincing sample
evidence that it is true.
Answer
Selected Answer:
• Question 15
4 out of 4 points
The average waiting time per customer at a fast food restaurant has been 7.5 minutes. The
customer waiting time has a normal distribution. The manager claims that the use of a new
cashier system will decrease the average customer waiting time in the store. A random
sample of 12 customer transactions has been recorded. At a significance level of .05, what
is the rejection point condition? We would reject the null hypothesis if:
Answer
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• Question 16
4 out of 4 points
When the level of confidence and sample standard deviation remain the same, a
confidence interval for a population mean based on a sample of n = 100 will be
______________ a confidence interval for a population mean based on a sample of n = 50.
Answer
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• Question 17
4 out of 4 points
When determining the sample size, if the value found is not an integer initially, the next
highest integer value will ____________ be chosen.
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• Question 18
4 out of 4 points
When conducting a hypothesis test about a single mean, other relevant factors held
constant, increasing the level of significance from .05 to .10 will reduce the probability of
a Type I error.
Answer
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• Question 19
4 out of 4 points
When the margin of error is added to and subtracted from the sample mean an interval is
formed that will contain m with probability of (1 – a).
Answer
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• Question 20
4 out of 4 points
As the level of significance α increases, we are more likely to reject the null hypothesis.
Answer
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• Question 21
4 out of 4 points
The average waiting time per customer at a fast food restaurant has been 7.5 minutes. The
customer waiting time has a normal distribution. The manager claims that the use of a new
cashier system will decrease the average customer waiting time in the store. Based on a
random sample of 16 customer transactions the mean waiting time is 6.3 minutes and the
standard deviation is 2 minutes per customer. What is the value of the test statistic?
Answer
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• Question 22
4 out of 4 points
When the population is normally distributed, population standard deviation σ is unknown,
and the sample size is n = 15; the confidence interval for the population mean µ is based
on:
Answer
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• Question 23
4 out of 4 points
When conducting a hypothesis test about a single mean, at a given level of significance, as
the sample size n increases, the power of the test:
Answer
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• Question 24
0 out of 4 points
In testing for the equality of means from two independent populations, if the null
hypothesis is rejected, the test could result in:
Answer
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• Question 25
4 out of 4 points
In a completely randomized ANOVA, other things equal as the sample means get closer to
each other, the probability of rejecting the null hypothesis:
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