Details of MATH 225N Week 8 Statistics Final Exam 2021
Week 8 Final Examscored
128 out of 160= 80%
QUESTION 1
Of the following pairs of events, which
... [Show More] pair has mutually exclusive events?
rolling a sum greater than 7 from two rolls of a standard die and rolling a 4 for the
first throw
drawing a 2 and drawing a 4 with replacement from a standard deck of cards
rolling a sum of 9 from two rolls of a standard die and rolling a 2 for the first roll
drawing a red card and then drawing a black card with replacement from a standard
deck of cards
QUESTION 2
Hugo averages 41 words per minute on a typing test with a standard deviation
of 7.5 words per minute. Suppose Hugo's words per minute on a typing test are
normally distributed. Let X= the number of words per minute on a typing test.
Then, X∼N(41,7.5).
Suppose Hugo types 45 words per minute in a typing test on Wednesday. The z-score
when x=45 is ________. This z-score tells you that x=45 is ________ standard
deviations to the ________ (right/left) of the mean, ________.
Correctly fill in the blanks in the statement above.
Select the correct answer below:
Suppose Hugo types 45 words per minute in a typing test on Wednesday. The zscore
when x=45 is −0.533. This z-score tells you that x=45 is 0.533 standard
deviations to the left of the mean, 41.
Suppose Hugo types 45 words per minute in a typing test on Wednesday. The zscore
when x=45 is −0.381. This z-score tells you that x=45 is 0.381 standard
deviations to the left of the mean, 41.
Suppose Hugo types 45 words per minute in a typing test on Wednesday. The zscore
when x=45 is 0.381. This z-score tells you that x=45 is 0.381 standard
deviations to the right of the mean, 41.
zscore
when x=45 is 0.533. This z-score tells you that x=45 is 0.533 standard
deviations to the right of the mean, 41.
QUESTION 3
A fitness center claims that the mean amount of time that a person spends at the gym
per visit is 33 minutes. Identify the null hypothesis, H0, and the alternative
hypothesis, Ha, in terms of the parameter μ.
Select the correct answer below:
H0: μ≠33; Ha: μ=33
H0: μ=33; Ha: μ≠33
H0: μ≥33; Ha: μ<33
H0: μ≤33; Ha: μ>33
QUESTION 4
A recent study suggested that 81% of senior citizens take at least one prescription
medication. Amelia is a nurse at a large hospital who would like to know whether the
percentage is the same for senior citizen patients who go to her hospital. She randomly
selects 59 senior citizens patients who were treated at the hospital and finds
that 49 of them take at least one prescription medication. What are the null and
alternative hypotheses for this hypothesis test?
{H0:p=0.81Ha:p>0.81
{H0:p≠0.81Ha:p=0.81
{H0:p=0.81Ha:p<0.81
{H0:p=0.81Ha:p≠0.81
QUESTION 5
A doctor notes her patient's temperature in degrees Fahrenheit every hour to make sure the
patient does not get a fever. What is the level of measurement of the data.
nominal
ordinal
interval
ratio
QUESTION 6
Assume the null hypothesis, H0, is: Jacob earns enough money to afford a luxury apartment.
Find the Type I error in this scenario.
Jacob thinks he does not earn enough money to afford the luxury apartment when, in fact,
he does.
Jacob thinks he does not earn enough money to afford the luxury apartment when, in fact,
he does not.
Jacob thinks he earns enough money to afford the luxury apartment when, in fact, he does
not.
Jacob thinks he earns enough money to afford the luxury apartment when, in fact, he does.
QUESTION 7
The population standard deviation for the heights of dogs, in inches, in a city
is 3.7 inches. If we want to be 95% confident that the sample mean is
within 2 inches of the true population mean, what is the minimum sample size that can
be taken?
z0.101.282z0.051.645z0.0251.960z0.012.326z0.0052.576
Use the table above for the z-score, and be sure to round up to the nearest integer.
ANSWER: 25 DOG HEIGHTS
QUESTION 8
Alice sells boxes of candy at the baseball game and wants to know the mean number of
boxes she sells. The numbers for the games so far are listed below.
16,14,14,21,15
Find the mean boxes sold.
ANSWER: MEAN= 16 BOXES
QUESTION 9
To test the effectiveness of a drug proposed to relieve symptoms of headache,
physicians included participants for a study. They gave the drug to one group and a
drug with no therapeutic effect to another group. Which group receives the placebo?
the physicians
the group that received the drug for headache
the group that received the drug with no therapeutic effect
all of the people in the study
QUESTION 10
John owns a computer repair service. For each computer, he charges $50 plus $45 per hour of
work. A linear equation that expresses the total amount of money John earns per computer
is y=50+45x. What are the independent and dependent variables? What is the y-intercept and
the slope?
The independent variable (x) is the amount of time John fixes a computer. The dependent
variable (y) is the amount, in dollars, John earns for a computer.
John charges a one-time fee of $50 (this is when x=0), so the y-intercept is 50. John
earns $45 for each hour he works, so the slope is 45.
The independent variable (x) is the amount, in dollars, John earns for a computer. The
dependent variable (y) is the amount of time John fixes a computer.
John charges a one-time fee of $45 (this is when x=0), so the y-intercept is 45. John
earns $50 for each hour he works, so the slope is 50.
The independent variable (x) is the amount, in dollars, John earns for a computer. The
dependent variable (y) is the amount of time John fixes a computer.
John charges a one-time fee of $50 (this is when x=0), so the y-intercept is 50. John
earns $45 for each hour he works, so the slope is 45.
The independent variable (x) is the amount of time John fixes a computer. The dependent
variable (y) is the amount, in dollars, John earns for a computer.
John charges a one-time fee of $45 (this is when x=0), so the y-intercept is 45. John
earns $50 for each hour he works, so the slope is 50.
QUESTION 11
Brayden tosses a coin 500 times. Of those 500 times, he observes heads a total
of 416 times. Calculations show that the probability of this occurring by chance is less
than 0.01, assuming the coin is fair. Determine the meaning of the significance level.
We expect that 416 of every 500 coin tosses will result in heads.
At the 0.01 level of significance, the coin is likely not a fair coin.
There is certainty that the coin is not a fair coin.
The results are not statistically significant at the 0.05 level of significance.
QUESTION 12
A researcher claims that the proportion of cars with manual transmission is less
than 10%. To test this claim, a survey checked 1000 randomly selected cars. Of
those cars, 95 had a manual transmission.
The following is the setup for the hypothesis test:
{H0:p=0.10Ha:p<0.10
Find the test statistic for this hypothesis test for a proportion. Round your answer
to 2 decimal places.
ANSWER: -0.53
QUESTION 13
An economist claims that the proportion of people who plan to purchase a fully electric
vehicle as their next car is greater than 65%.
To test this claim, a random sample of 750 people are asked if they plan to purchase a
fully electric vehicle as their next car Of these 750 people, 513 indicate that they do
plan to purchase an electric vehicle.
The following is the setup for this hypothesis test:
H0:p=0.65
Ha:p>0.65
In this example, the p-value was determined to be 0.026.
Come to a conclusion and interpret the results for this hypothesis test for a proportion
(use a significance level of 5%.)
The decision is to reject the Null Hypothesis.
The conclusion is that there is enough evidence to support the claim.
The decision is to fail to reject the Null Hypothesis.
The conclusion is that there is not enough evidence to support the claim.
QUESTION 14
A medical researcher claims that the proportion of people taking a certain medication
that develop serious side effects is 12 [Show Less]