Allied MAT130 final exam

1. Provide an appropriate
response.
A teacher was
interested in knowing how much tax people pay in the United States. She selected a simple random sample of her
friends and asked them about their taxes.
Is this sample likely to be representative of all adults in the United
States?

2. Form a conclusion about
statistical significance. Do not make
any formal calculations. Either use the
results provided or make subjective judgments about the results.
A manufacturer of
laptop computers claims that only 1% of their computers are defective. In a sample of 600 computers, it was found
that 3% were defective. If the
proportion of defectives were really only 1%, there would be less than 1 chance
in 1000 of getting such a large proportion of defective laptops in the
sample. Is there statistically
significant evidence against the manufacturer’s claim? Why or why not?

3. Use critical thinking
to address the key issue.
A researcher
published this survey result: “74% of people would be willing to spend 10
percent more for energy from a non-polluting source”. The survey question was announced on a
national radio show and 1,200 listeners responded by calling in. What is wrong with this survey?

4. Provide an appropriate
response.
An advertisement
for a heating pad says that is can reduce back pain by 200%. What is wrong with this statement?

5. Provide an appropriate
response.
Helene claimed
that the expected value when rolling a fair die was 3.5. Steve said that wasn’t possible. He said that the expected value was the most
likely value in a single roll of the die, and since it wasn’t possible for a
die to turn up with a value of 3.5, the expected value couldn’t possibly be
3.5. Who is right? Explain.

6. Provide an appropriate
response.
Do probability
distributions measure what did happen or what will probably happen? How do we use probability distributions to
make decisions?

7. Provide an appropriate
response.
A poll of 1700
randomly selected students in grades 6 through 8 was conducted and found that
53% enjoy playing sports. Is the 53%
result a statistic or a parameter?
Explain.

8. Provide an appropriate
response.
Define
P-values. Explain the two methods of
interpreting P-values.

9. Solve the problem. What do you conclude about the claim
below? Do not use formal procedures or
exact calculations. Use only the rare
event rule and make a subjective estimate to determine whether then event is
likely.
Claim: An employee
of a company is equally likely to take a sick day on any day of the week. Last year, the total number of sick days
taken by all the employees of the company was 143. Of these, 52 were Mondays, 14 were Tuesdays,
17 were Wednesdays, 17 were Thursdays, and 43 were Fridays.

10. Provide an appropriate
response.
Define independent
and dependent samples and give an example of each.
Independent samples
are samples where one observation does not affect the outcome of another
observation. One example is a sample of the weights of individuals selected at
random. We can assume that one person’s weight does not affect any other
person’s weight.

11. Describe the error in
the stated conclusion.
Given: There is no
significant linear correlation between scores on a math test and scores on a
verbal test. Conclusion: There is no
relationship between scores on the math test and scores on the verbal test.

12. Provide an appropriate
response.
List the
advantages and disadvantages of nonparametric tests.

13. Provide an appropriate
response.
Describe the sign
test. What types of hypotheses is it
used to test? What is the underlying
concept?

14. Provide an appropriate
response.
Describe the
Wilcoxon rank-sum test. What type of
hypotheses is it used to test? What
assumptions are made for this test? What
is the underlying concept?

15. Provide an appropriate
response.
Describe a run
chart and give an example. Refer to the
values on each of the axes as you describe the run chart.