ashworth college MA260 online exam 8 latest 2015 december

Part 1 of 2 – 30.0/
50.0 Points

Question 1 of 40
2.5/ 2.5 Points
At one school, the mean amount of time that tenth-graders
spend watching television each week is 18.4 hours. The principal introduces a
campaign to encourage the students to watch less television. One year later,
the principal wants to perform a hypothesis test to determine whether the
average amount of time spent watching television per week has decreased.
Formulate the null and alternative hypotheses for the study
described.

A.
Ho: µ = 18.4 hours
H a : µ ¹ 18.4 hours

B.
Ho: µ = 18.4 hours
H a : µ < 18.4 hours C. Ho: µ ³ 18.4 hours H a : µ < 18.4 hours D. Ho: µ = 18.4 hours H a : µ > 18.4 hours

Question 2 of 40
0.0/ 2.5 Points
A right-tailed test is conducted at the 5% significance
level. Which of the following z-scores is the smallest one in absolute value
that leads to rejection of the null hypothesis?  
A. 1.61
B. 1.85
C. -1.98
D. -2.06

Question 3 of 40
2.5/ 2.5 Points
The principal of a middle school claims that annual incomes
of the families of the seventh-graders at his school vary more than the annual
incomes of the families of the seventh-graders at a neighboring school, which
have variation described by s = $13,700. Assume that a hypothesis test of the
claim has been conducted and that the conclusion of the test was to reject the
null hypothesis. Identify the population to which the results of the test
apply.

A. The current
seventh graders at the principal’s school
B. Seventh graders’
families at the school with a standard deviation of $13,700
C. All of the
families of the class of seventh graders at the principal’s school
D. All seventh
graders’ families

Question 4 of 40
2.5/ 2.5 Points
A manufacturer claims that the mean amount of juice in its
16 ounce bottles is 16.1 ounces. A consumer advocacy group wants to perform a
hypothesis test to determine whether the mean amount is actually less than
this. The mean volume of juice for a random sample of 70 bottles was 15.94
ounces. Do the data provide sufficient evidence to conclude that the mean
amount of juice for all 16-ounce bottles, µ, is less than 16.1 ounces? Perform
the appropriate hypothesis test using a significance level of 0.10. Assume that
s = 0.9 ounces.  

A.
The z of – 1.49 provides sufficient evidence to conclude
that the mean amount of juice is less than 16.1 oz.

B.
The z of – 1.49 does not provide sufficient evidence to
conclude that the mean amount of juice is less than 16.1 oz.

C.
The z of – 0.1778 does not provide sufficient evidence to
conclude that the mean amount of juice is less than 16.1 oz.

D.
The z of – 0.1778 provides sufficient evidence to conclude
that the mean amount of juice is less than 16.1 oz.

Question 5 of 40
0.0/ 2.5 Points
A two-tailed test is conducted at the 5% significance level.
What is the left tail percentile required to reject the null hypothesis?
A. 97.5%
B. 5%
C. 2.5%
D. 95%

Question 6 of 40
2.5/ 2.5 Points
In the past, the mean running time for a certain type of
flashlight battery has been 8.0 hours. The manufacturer has introduced a change
in the production method and wants to perform a hypothesis test to determine
whether the mean running time has increased as a result. The hypotheses are:

H0 : µ = 8.0 hours

Ha : µ > 8.0 hours

Explain the meaning of a Type II error.

A. Concluding that µ
> 8.0 hours when in fact µ > 8.0 hours
B. Failing to reject
the hypothesis that µ = 8.0 hours when in fact µ >
8.0 hours
C. Concluding that µ
> 8.0 hours
D. Failing to reject
the hypothesis that µ = 8.0 hours when in fact µ = 8.0 hours

Question 7 of 40
2.5/ 2.5 Points
A skeptical paranormal researcher claims that the proportion
of Americans that have seen a UFO is less than 1 in every one thousand. State
the null hypothesis and the alternative hypothesis for a test of significance.

A.
H0: p = 0.001 Ha:
p > 0.001

B.
H0: p = 0.001 Ha:
p < 0.001 C. H0: p > 0.001
Ha: p = 0.001

D.
H0: p < 0.001 Ha: p = 0.001 Question 8 of 40 2.5/ 2.5 Points In 1990, the average duration of long-distance telephone calls originating in one town was 9.3 minutes. A long-distance telephone company wants to perform a hypothesis test to determine whether the average duration of long-distance phone calls has changed from the 1990 mean of 9.3 minutes. Formulate the null and alternative hypotheses for the study described. A. Ho: µ = 9.3 minutes H a : µ < 9.3 minutes B. Ho: µ = 9.3 minutes H a : µ > 9.3 minutes

C.
Ho: µ = 9.3 minutes
H a : µ ¹ 9.3 minutes

D.
Ho: µ ¹ 9.3 minutes
H a : µ = 9.3 minutes

Question 9 of 40
0.0/ 2.5 Points
A study of a brand of “in the shell peanuts” gives the
following results:

A significant event at the 0.01 level is a fan getting a bag
with how many peanuts?

A. 30 peanuts
B. 25 or 30 peanuts
C. 25 or 55 peanuts
D. 25, 30 or 55
peanuts

Question 10 of 40
2.5/ 2.5 Points
A consumer group claims that the mean running time for a
certain type of flashlight battery is not the same as the manufacturer’s
claims. Determine the null and alternative hypotheses for the test described.

A.
H0: µ = Manufacturer’s claims Ha: µ < Manufacturer’s claims B. H0: µ = Manufacturer’s claims Ha: µ ¹ Manufacturer’s claims C. H0: µ = Manufacturer’s claims Ha: µ > Manufacturer’s claims

D.
H0: µ ¹ Manufacturer’s claims Ha: µ = Manufacturer’s claims

Question 11 of 40
2.5/ 2.5 Points
A psychologist claims that more than 29 percent of the
professional population suffers from problems due to extreme shyness. Assuming
that a hypothesis test of the claim has been conducted and that the conclusion
is failure to reject the null hypothesis, state the conclusion in non-technical
terms.
A. There is
sufficient evidence to support the claim that the true proportion is less than
29 percent.
B. There is not
sufficient evidence to support the claim that the true proportion is greater
than 29 percent.
C. There is
sufficient evidence to support the claim that the true proportion is equal to
29 percent.
D. There is
sufficient evidence to support the claim that the true proportion is greater
than 29 percent.

Question 12 of 40
2.5/ 2.5 Points
A supplier of DVDs claims that no more than 1% of the DVDs
are defective. In a random sample of 600 DVDs, it is found that 3% are
defective, but the supplier claims that this is only a sample fluctuation. At
the 0.01 level of significance, test the supplier’s claim that no more than 1%
are defective.
A. Do not reject the
null hypothesis and conclude that there is evidence to support the claim that
more than 1% of the DVDs are defective.
B. Reject the null
hypothesis and conclude that there is insufficient evidence to support the
claim that more than 1% of the DVDs are defective.
C. Do not reject the
null hypothesis and conclude that there is insufficient evidence to support the
claim that more than 1% of the DVDs are defective.
D. Reject the null
hypothesis and conclude that there is sufficient evidence to support the claim
that more than 1% of the DVDs are defective.

Question 13 of 40
0.0/ 2.5 Points
A two-tailed test is conducted at the 5% significance level.
Which of the z-scores below is the smallest one that leads to rejection of the
null hypothesis?
A. 1.12
B. 1.48
C. 1.84
D. 2.15

Question 14 of 40
0.0/ 2.5 Points

If a fan purchased a bag with 30 peanuts, what is the lowest
level at which this would be a significant event?

A. 0.05
B. 0.025
C. 0.01
D. It is not
significant at any of the levels given

Question 15 of 40
0.0/ 2.5 Points

without computing a P-value, determine whether the alternate
hypothesis is supported and give a reason for your conclusion.

A.
is less than 1 standard deviation above the claimed mean.

B.
is more than 4 standard deviations above the claimed mean.

C.
is less than 1 standard deviation above the claimed mean.

D.
is more than 4 standard deviations above the claimed mean.

Question 16 of 40
0.0/ 2.5 Points
The owner of a football team claims that the average
attendance at home games is over 3000, and he is therefore justified in moving
the team to a city with a larger stadium. Assuming that a hypothesis test of
the claim has been conducted and that the conclusion is failure to reject the
null hypothesis, state the conclusion in non-technical terms.
A. There is
sufficient evidence to support the claim that the mean attendance is greater
than 3000.
B. There is
sufficient evidence to support the claim that the mean attendance is equal to
3000.
C. There is not
sufficient evidence to support the claim that the mean attendance is greater
than 3000.
D. There is not
sufficient evidence to support the claim that the mean attendance is less than
3000.

Question 17 of 40
0.0/ 2.5 Points
A long-distance telephone company claims that the mean
duration of long-distance telephone calls originating in one town was greater
than 9.4 minutes, which is the average for the state. Determine the conclusion
of the hypothesis test assuming that the results of the sampling do not lead to
rejection of the null hypothesis.
A. Conclusion:
Support the claim that the mean is less than 9.4 minutes.
B. Conclusion:
Support the claim that the mean is greater than 9.4 minutes.
C. Conclusion:
Support the claim that the mean is equal to 9.4 minutes.
D. Conclusion: Do
not support the claim that the mean is greater than 9.4 minutes.

Question 18 of 40
2.5/ 2.5 Points
z = 1.8 for Ha: µ
> claimed value. What is the P-value
for the test?  

A. 0.9641
B. 3.59
C. 96.41
D. 0.0359

Question 19 of 40
2.5/ 2.5 Points
A consumer advocacy group claims that the mean amount of
juice in a 16
ounce bottled drink is not 16 ounces, as stated by the
bottler.
Determine the null and alternative hypotheses for the test
described.
A.
H0: µ = 16 ounces
Ha: µ < 16 ounces B. H0: µ ¹ 16 ounces Ha: µ = 16 ounces C. H0: µ = 16 ounces Ha: µ > 16 ounces

D.
H0: µ = 16 ounces
Ha: µ ¹ 16 ounces

Question 20 of 40
2.5/ 2.5 Points
A poll of 1,068 adult Americans reveals that 52% of the
voters surveyed prefer the Democratic candidate for the presidency. At the 0.05
significance level, test the claim that more than half of all voters prefer the
Democrat.
A. Reject the null
hypothesis. Conclude that there is insufficient evidence that more than half of
all voters prefer Democrats.
B. Do not reject the
null hypothesis. Conclude that there is sufficient evidence that more than half
of all voters prefer Democrats.
C. Reject the null
hypothesis. Conclude that there is sufficient evidence that more than half of
all voters prefer Democrats.
D. Do not reject the
null hypothesis. Conclude that there is insufficient evidence that more than
half of all voters prefer Democrats.

Part 2 of 2 – 35.0/
50.0 Points

Question 21 of 40
0.0/ 2.5 Points
The margin of error in estimating the population mean of a
normal population is E = 9.3 when the sample size is 15. If the sample size had
been 18 and the sample standard deviation did not change, would the margin of
error be larger or smaller than 9.3? Explain your answer.

A. Smaller. E
decreases as the square root of the sample size gets larger.
B. Smaller. E
increases as the square root of the sample size gets larger.
C. Larger. E
decreases as the square root of the sample size gets larger.
D. Larger. E
increases as the square root of the sample size gets larger.

Question 22 of 40
2.5/ 2.5 Points
A 95% confidence interval for the mean of a normal
population is found to be 15.6 < µ < 25.2. What is the margin of error? A. 3.9 B. 4.8 C. 4.9 D. 3.7 Question 23 of 40 2.5/ 2.5 Points One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The critical value of X2 for a 2 x 2 table using a 0.05 significance level is 3.841. If the value of the X2 statistic is 3.179, state your conclusion about the relationship between gender and colorblindness. A. Do not reject H0. B. Reject H0. C. There is sufficient evidence to support the claim that gender and colorblindness are not related. D. There is not sufficient evidence to accept or reject H0. Question 24 of 40 2.5/ 2.5 Points A 95% confidence interval for the mean of a normal population is found to be 17.6 < µ < 23.6. What is the margin of error? A. 2.0 B. 2.7 C. 3.0 D. 4.0 Question 25 of 40 2.5/ 2.5 Points The following data were analyzed using one-way analysis of variance. A B C 34 27 19 26 23 31 31 29 22 28 21 22 Which one of the following statements is correct? A. The purpose of the analysis is to determine whether the groups A, B, and C are independent. B. The purpose of the analysis is to test the hypothesis that the population means of the three groups are equal. C. The purpose of the analysis is to test the hypothesis that the population variances of the three groups are equal. D. The purpose of the analysis is to test the hypothesis that the sample means of the three groups are equal. Question 26 of 40 2.5/ 2.5 Points The margin of error in estimating the population mean of a normal population is E = 9.3 when the sample size is 15. If the sample size had been 25 and the sample standard deviation did not change, would the margin of error be larger or smaller than 9.3? A. Smaller. E increases as the square root of the sample size gets larger. B. Smaller. E decreases as the square root of the sample size gets larger. C. Larger. E decreases as the square root of the sample size gets larger. D. Larger. E increases as the square root of the sample size gets larger. Question 27 of 40 0.0/ 2.5 Points A golfer wished to find a ball that would travel more than 180 yards when hit with his 5-iron with a club speed of 90 miles per hour. He had a golf equipment lab test a low compression ball by having a robot swing his club 7 times at the required speed. State the null and alternative hypotheses for this test. A. H0: µ = 180; Ha: µ > 180

B.
H0: µ > 180; Ha: µ > 180

C.
H0: µ < 180; Ha: µ > 180

D.
H0: µ = 180; Ha: µ < 180 Question 28 of 40 2.5/ 2.5 Points A golfer wished to find a ball that would travel more than 160 yards when hit with his 7-iron with a club speed of 90 miles per hour. He had a golf equipment lab test a low compression ball by having a robot swing his club 8 times at the required speed. State the null and alternative hypotheses for this test. A. H0: µ = 160; Ha: µ > 150

B.
H0: µ = 150; Ha: µ > 150

C.
H0: µ = 160; Ha: µ > 160

D.
H0: µ = 140; Ha: µ > 160

Question 29 of 40
0.0/ 2.5 Points
A golfer wished to find a ball that would travel more than
180 yards when hit with his 5-iron with a club speed of 90 miles per hour. He
had a golf equipment lab test a low compression ball by having a robot swing
his club 7 times at the required speed.

Data from this test resulted in a sample mean of 184.2 yards
and a sample standard deviation of 5.8 yards. Assuming normality, carry out a
hypothesis test at the 0.05 significance level to determine whether the ball
meets the golfer’s requirements. Use the partial t-table below.

Area in one tail
0.025 0.05
Area in two tails
Degrees of
Freedom
n – 1 0.05 0.10
6 2.447 1.943
7 2.365 1.895
8 2.306 1.860
9 2.262 1.833
A.
Reject the null hypothesis. The data do not provide
sufficient evidence that the average distance is greater than 180 yards.

B. Reject the null
hypothesis. The data do provide sufficient evidence that the average distance
is greater than 180 yards.
C. Do not reject the
null hypothesis. The data do provide sufficient evidence that the average
distance is greater than 180 yards.
D. Do not reject the
null hypothesis. The data do not provide sufficient evidence that the average
distance is greater than 180 yards.

Question 30 of 40
0.0/ 2.5 Points
The __________ test statistic is for the one-way analysis of
variance.
A. P-Value
B. t
C. F
D. p

Question 31 of 40
2.5/ 2.5 Points
A simple random sample from a normal distribution is taken
in order to obtain a 95% confidence interval for the population mean. If the
sample size is 8, the sample mean x̄ is 22, and the sample standard deviation s
is 6.3, what is the margin of error? Show your answer to 2 decimal places.

A. df = 7; E = 3.3445.38
= 5.6566
B. df = 8; E =
3.3445.38 = 5.6566
C. df = 6; E =
2.3656.38 = 5.769
D. df = 7; E =
2.3656.38 = 5.869

Question 32 of 40
0.0/ 2.5 Points
One hundred people are selected at random and tested for
colorblindness to determine whether gender and colorblindness are independent.
The following counts were observed.

Colorblind Not Colorblind Total
Male 7 53 60
Female 1 39 40
Total 8 92 100
Find the value of the X2 statistic for the data above.

A. 1.325
B. 1.318
C. 1.286
D. 1.264

Question 33 of 40
0.0/ 2.5 Points
Which of the following statements is true?

A.
The t distribution can be used when finding a confidence
interval for the population mean whenever the sample size is small.

B. The p
distribution can be used when finding a confidence interval for the population
mean whenever the sample size is small.
C. The t
distribution cannot be used when finding a confidence interval for the
population mean whenever the sample size is small.
D. The p
distribution cannot be used when finding a confidence interval for the sample
mean whenever the sample size is small.

Question 34 of 40
2.5/ 2.5 Points
A golfer wished to find a ball that would travel more than
160 yards when hit with his 7-iron with a club speed of 90 miles per hour. He
had a golf equipment lab test a low compression ball by having a robot swing
his club 8 times at the required speed.

Data from this test resulted in a sample mean of 163.2 yards
with a sample standard deviation of 5.8 yards. Assuming normality, carry out a
hypothesis test at the 0.05 significance level to determine whether the ball
meets the golfer’s requirements. Use the partial t-table below to solve this
problem.

Area in one tail
0.025 0.05
Area in two tails
Degrees of
Freedom
n – 1 0.05 0.10
6 2.447 1.943
7 2.365 1.895
8 2.306 1.860
9 2.262 1.833
A.
Do not reject the null hypothesis. The data do not provide
sufficient
evidence that the average distance is greater than 160
yards.

B. Reject the null
hypothesis. The data does provide sufficient evidence that the average distance
is greater than 160 yards.
C. t= 1.2334;
Critical value = 1.992
D. Insufficient
information to answer this question.

Question 35 of 40
2.5/ 2.5 Points
One hundred people are selected at random and tested for
colorblindness to determine whether gender and colorblindness are independent.
The following counts were observed.

Colorblind Not Colorblind Total
Male 8 52 60
Female 2 38 40
Total 10 90 100
If gender and colorblindness are independent, find the
expected values corresponding to the four combinations of gender and
colorblindness, and enter them in the following table along with row and column
totals.

Colorblind Not Colorblind Total
Male
Female
Total

A. Male Colorblind
6.0; Male Not Colorblind 54.0
B. Male Colorblind
7.0; Male Not Colorblind 53.0
C. Male Colorblind
8.0; Male Not Colorblind 52.0
D. Male Colorblind
6.0; Male Not Colorblind 53.0

Question 36 of 40
2.5/ 2.5 Points
One hundred people are selected at random and tested for
colorblindness to determine whether gender and colorblindness are independent.
The following counts were observed.

Colorblind Not Colorblind Total
Male 7 53 60
Female 1 39 40
Total 8 92 100
State the null and alternative hypothesis for the
information above.

A.
H0: Colorblindness and gender are dependent characteristics.
Ha: Colorblindness and gender are related in some way.

B.
H0: Colorblindness and gender are independent
characteristics.
Ha: Colorblindness and gender are not related in any way.

C.
H0: Colorblindness and gender are dependent characteristics.
Ha: Colorblindness and gender are not related in any way.

D.
H0: Colorblindness and gender are independent
characteristics.
Ha: Colorblindness and gender are related in some way.

Question 37 of 40
2.5/ 2.5 Points
Which of the following statements is true?

A. The t
distribution cannot be used when finding a confidence interval for the
population mean with a small sample whenever the sample comes from a symmetric
population.
B. The t
distribution can be used when finding a confidence interval for the population
mean with a small sample whenever the sample comes from a symmetric population.

C. The p
distribution can be used when finding a confidence interval for the population
mean with a small sample whenever the sample comes from a symmetric population.

D. The p
distribution can be used when finding a confidence interval for the population
mean with a small sample whenever the sample comes from a symmetric population.

Question 38 of 40
2.5/ 2.5 Points
One hundred people are selected at random and tested for
colorblindness to determine whether gender and colorblindness are independent.
The following counts were observed.

Colorblind Not Colorblind Total
Male 8 52 60
Female 2 38 40
Total 10 90 100
Find the value of the X2 statistic for the data above.

A. 1.463
B. 1.852
C. 1.947
D. 1.949

Question 39 of 40
2.5/ 2.5 Points
A golfer wished to find a ball that would travel more than
170 yards when hit with his 6-iron with a club head speed of 90 miles per hour.
He had a golf equipment lab test a low compression ball by having a robot swing
his club 12 times at the required speed. State the null and alternative
hypotheses for this test.

A.
H0: µ > 170; Ha: µ = 170

B.
H0: µ < 170; Ha: µ = 170 C. H0: µ = 170; Ha: µ > 170

D.
H0: µ = 160; Ha: µ > 160

Question 40 of 40
2.5/ 2.5 Points
One hundred people are selected at random and tested for
colorblindness to determine whether gender and colorblindness are independent.
The following counts were observed.

Colorblind Not Colorblind Total
Male 8 52 60
Female 2 38 40
Total 10 90 100
State the null and alternative hypothesis for the test
associated with this data.

A.
H0: Colorblindness and gender are dependent characteristics.
Ha: Colorblindness and gender are not related in any way.

B.
H0: Colorblindness
and gender are dependent characteristics.
Ha: Colorblindness
and gender are related in some way.

C.
H0: Colorblindness and gender are independent
characteristics.
Ha: Colorblindness and gender are not related in any way.

D.
H0: Colorblindness and gender are independent characteristics.
Ha: Colorblindness and gender are related in some way.