Question 1 of 20
1.0/ 1.0 Points
A severe storm has an average peak wave height of 16.4 feet
for waves hitting the shore. Suppose that a storm is in progress with a severe
storm class rating. Let us say that we want to set up a statistical test to see
if the wave action (i.e., height) is dying down or getting worse. If you wanted
to test the hypothesis that the waves are dying down, what would you use for
the alternate hypothesis? Is the P-value area on the left, right, or on both
sides of the mean?
Correct A.H1: f$mu
f$ is less than 16.4 feet; the P-value
area is on the left of the mean
B.H1: f$mu f$ is greater than 16.4 feet; the P-value area
is on both sides of the mean
C.H1: f$mu f$ is greater than 16.4 feet; the P-value area
is on the left of the mean
D.H1: f$mu f$ is not equal to 16.4 feet; the P-value area
is on the right of the mean
Answer Key:
Question 2 of 20
1.0/ 1.0 Points
A lab technician is tested for her consistency by taking
multiple measurements of cholesterol levels from the same blood sample. The
target accuracy is a variance in measurements of 1.2 or less. If the lab
technician takes 16 measurements and the variance of the measurements in the
sample is 2.2, does this provide enough evidence to reject the claim that the
lab technician’s accuracy is within the target accuracy?
State the null and alternative hypotheses.
A.H0: s2 ? 1.2, H1:
s2 = 1.2
B.H0: s2 < 1.2,
H1: s2 ? 1.2
C.H0: s2 ? 1.2, H1:
s2 ? 1.2
Correct D.H0: s2 ?
1.2, H1: s2 > 1.2
Answer Key:
Question 3 of 20
0.0/ 1.0 Points
A null hypothesis can only be rejected at the 5%
significance level if and only if:
Incorrect
A.the null hypotheses includes sampling error
B.a 95% confidence
interval includes the hypothesized value of the parameter
C.a 95% confidence
interval does not include the hypothesized value of the parameter
D.the null hypothesis
is biased
Answer Key:
Question 4 of 20
1.0/ 1.0 Points
The alternative hypothesis is also known as the:
A.optional hypothesis
Correct B.research
hypothesis
C.null hypothesis
D.elective hypothesis
Answer Key:
Question 5 of 20
1.0/ 1.0 Points
The null and alternative hypotheses divide all possibilities
into:
A.two sets that
overlap
B.two sets that may
or may not overlap
Correct C.two
non-overlapping sets
D.as many sets as
necessary to cover all possibilities
Answer Key:
Question 6 of 20
1.0/ 1.0 Points
A type I error occurs when the:
Correct A.null
hypothesis is incorrectly rejected when it is true
B.sample mean differs
from the population mean
C.null hypothesis is
incorrectly accepted when it is false
D.test is biased
Answer Key:
Question 7 of 20
0.0/ 1.0 Points
A lab technician is
tested for her consistency by taking multiple measurements of cholesterol
levels from the same blood sample. The target accuracy is a variance in
measurements of 1.2 or less. If the lab technician takes 16 measurements and
the variance of the measurements in the sample is 2.2, does this provide enough
evidence to reject the claim that the lab technician’s accuracy is within the
target accuracy?
At the a = .01 level of significance, what is your
conclusion?
A.
Reject
H0. At the f$alpha f$ = .01 level of significance, there is not
enough evidence to support the claim that this technician’s true variance is
larger than the target accuracy.
Incorrect
B.Reject H0. At the f$alpha f$ = .01
level of significance, there is enough evidence to support the claim that this
technician’s variance is larger than the target accuracy.
C.Do not reject H0.
At the f$alpha f$ = .01 level of
significance there is not sufficient evidence to suggest that this technician’s
true variance is greater than the target accuracy.
D.Cannot determine
Answer Key:
Question 8 of 20
1.0/ 1.0 Points
Smaller p-values indicate more evidence in support of the:
Correct A.alternative
hypothesis
B.quality of the
researcher
C.null hypothesis
D.the reduction of
variance
Answer Key:
Question 9 of 20
1.0/ 1.0 Points
In an article appearing in Today’s Health a writer states
that the average number of calories in a serving of popcorn is 75. To determine
if the average number of calories in a serving of popcorn is different from 75,
a nutritionist selected a random sample of 20 servings of popcorn and computed
the sample mean number of calories per serving to be 78 with a sample standard
deviation of 7.
State the null and alternative hypotheses.
A.H0: f$mu f$ f$leq f$
75, H1: f$mu f$ > 75
Correct B.H0: f$mu
f$ = 75, H1: f$mu f$ ? 75
C.H0: f$mu f$ f$geq f$
75, H1: f$mu f$ < 75
D.H0: f$mu f$ = 75, H1: f$mu f$ > 75
Answer Key:
Question 10 of 20
1.0/ 1.0 Points
The “Pizza Hot” manager commits a Type I error if he/she is
A.staying with old
style when new style is better
B.staying with old
style when new style is no better than old style
C.switching to new
style when it is better than old style
Correct D.switching to
new style when it is no better than old style
Answer Key:
Question 11 of 20
0.0/ 1.0 Points
You conduct a hypothesis test and you observe values for the
sample mean and sample standard deviation when n = 25 that do not lead to the
rejection of H0. You calculate a p-value of 0.0667. What will happen to the
p-value if you observe the same sample mean and standard deviation for a sample
size larger than 25?
A.The p – value
increases
B.The p – value
decreases
Incorrect
C.The p – value may increase or decrease
D.The p – value stays
the same
Answer Key:
Part 2 of 3 – 3.0/
6.0 Points
Question 12 of 20
0.0/ 1.0 Points
Accepted characters: numbers, decimal point markers (period
or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000),
“E” or “e” (used in scientific notation). NOTE: For
scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where
“a” and “b” need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is
valid whereas {9i} is not.
A survey determines that mint chocolate chip is the favorite
ice cream flavor of 6% of consumers. An ice cream shop determines that of 240
customers, 18 customers stated their preference for mint chocolate chip.
Find the P-value that would be used to determine if the
percentage of customers who prefer mint chocolate chip ice has increased at a
5% level of significance.
P-value: Correct.3278
Round your answer to four decimal places as necessary.
Answer Key: 0.1635|0.1639
Feedback: This is a right-tail hypothesis test with a test
statistic of z = 0.978492.
Question 13 of 20
1.0/ 1.0 Points
Accepted characters: numbers, decimal point markers (period
or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000),
“E” or “e” (used in scientific notation). NOTE: For scientific
notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where
“a” and “b” need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is
valid whereas {9i} is not.
The ABC battery company claims that their batteries last 100
hours, on average. You decide to conduct a test to see if the company’s claim
is true. You believe that the mean life may be different from the 100 hours the
company claims. You decide to collect data on the average battery life (in
hours) of a random sample of n = 20 batteries. Some of the information related
to the hypothesis test is presented below.
Test of H0: f$mu f$
= 100 versus H1: f$mu
eq f$ 100
Sample mean 98.5
Std error of mean 0.777
Assuming the life length of batteries is normally
distributed, if you wish to conduct this test at the 0.05 level of
significance, what are the critical values that you should use? Place the
smaller critical value, rounded to 3 decimal places, in the first blank. For
example, -1.234 would be a legitimate entry.
Correct-2.093 . Place the larger
critical value, rounded to 3 decimal places, in the second blank. For example, 1.234 would be a legitimate
entry. Correct2.093
Answer Key: –
Question 14 of 20
1.0/ 1.0 Points
Accepted characters: numbers, decimal point markers (period
or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000),
“E” or “e” (used in scientific notation). NOTE: For
scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where
“a” and “b” need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is
valid whereas {9i} is not.
A medical doctor wishes to test the claim that the standard
deviation of the systolic blood pressure of deep sea divers is less than 450.
To do so, she selected a random sample of 20 divers and found s = 432.
Assuming that the systolic blood pressures of deep sea
divers are normally distributed, if the doctor wanted to test her research
hypothesis at the .01 level of significance, what is the critical value?
Place your answer, rounded to 3 decimal places, in the
blank. For example, 4.567 would be a legitimate entry. Correct7.633
Answer Key:
Question 15 of 20
0.0/ 1.0 Points
Accepted characters: numbers, decimal point markers (period
or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000),
“E” or “e” (used in scientific notation). NOTE: For scientific
notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where
“a” and “b” need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is
valid whereas {9i} is not.
Suppose a firm that produces light bulbs wants to know
whether it can say that its light bulbs typically last more than 1500 hours.
Hoping to find support for their claim, the firm collects a random sample of n
= 25 light bulbs and records the lifetime (in hours) of each bulb. The
information related to the hypothesis test is presented below.
Test of H0: f$mu leq f$
1500 versus H1: f$ mu f$ >
1500
Sample mean 1509.5
Std error of mean 4.854
Assuming the life length of this type of lightbulb is normally
distributed, what is the p-value associated with this test? Place your answer,
rounded to 3 decimal places in the blank. For example, .123 would be a
legitimate entry. Correct1.711
Answer Key
Question 16 of 20
1.0/ 1.0 Points
Accepted characters: numbers, decimal point markers (period
or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000),
“E” or “e” (used in scientific notation). NOTE: For
scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where
“a” and “b” need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is
valid whereas {9i} is not.
The ABC battery company claims that their batteries last at
least 100 hours, on average. Your experience with their batteries has been
somewhat different, so you decide to conduct a test to see if the company’s
claim is true. You believe that the mean life is actually less than the 100
hours the company claims. You decide to collect data on the average battery
life (in hours) of a random sample of n = 20 batteries. Some of the information
related to the hypothesis test is presented below.
Test of H0: f$mu geq
f$ 100 versus H1: f$mu< f$ 100
Sample mean 98.5
Std error of mean 0.777
Assuming the life length of batteries is normally
distributed, what is the p-value associated with this test? Place your answer,
rounded to 3 decimal places in the blank. For example, 0.0234 would be a
legitimate entry. Correct.0344
Answer Key:
Question 17 of 20
0.0/ 1.0 Points
Accepted characters: numbers, decimal point markers (period
or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000),
“E” or “e” (used in scientific notation). NOTE: For
scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where
“a” and “b” need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is
valid whereas {9i} is not.
A statistician wishes to test the claim that the standard
deviation of the weights of firemen is greater than 25 pounds. To do so, she
selected a random sample of 30 firemen and found s = 27.2 pounds.
Assuming that the weights of firemen are normally distributed,
if the statistician wanted to test her research hypothesis at the .05 level of
significance, what is the critical value?
Place your answer, rounded to 3 decimal places, in the
blank. For example, 23.456 would be a legitimate entry. Correct34.329
Answer Key:
Part 3 of 3 – 3.0/
3.0 Points
Question 18 of 20
1.0/ 1.0 Points
Sample evidence is statistically significant at the f$alpha
f$ level only if the p–value is larger
than f$alpha f$ .
Correct
True
False
Answer Key:
Question 19 of 20
1.0/ 1.0 Points
If a null hypothesis about a population mean is rejected at
the 0.025 level of significance, then it must also be rejected at the 0.01
level.
Correct
True
False
Answer Key:
Question 20 of 20
1.0/ 1.0 Points
A low p–value provides evidence for accepting the null
hypothesis and rejecting the alternative.
Correct
True
False
Answer Key:
