QNT 561 Week 3 Quiz

QNT
561 Week 3 Quiz

1. What is
the level of significance of a test of hypothesis?
2. For each
of the following rejection regions, sketch the sampling distribution for
z and indicate the location of the rejection region and determine the
probability that a Type I error will be made:
z1.645,zz>1.96, z>2.575
3. Several
years ago, a government agency reported the default rate on a certain type of
loan at 0.055. Set up the null and alternative hypotheses to determine if the
default rate this year is less than 0.055.
4. For the a
and observed significance level (p-value)pair, indicate whether the null
hypothesis would be rejected.
a=0.05
p-value=0.45
5.
A study
analyzes recent incidents involving terrorist attacks.
a. Do the
data indicate that the true mean number of suicide bombings for all terrorist
group attacks against this country differs from 3.5? Use a =0.01,
p-value=0.0000
b.A 99%
confidence interval for the mean of the population was found to be 1.85±0.837.
c. Do the
inferences derived from part a and be agree?
d.What
assumptions about the data must be true for the inferences to be valid?
e. Comment
on the validity of the inference.
6. Suppose
41 of 111 randomly selected shoppers believe that “Made in USA” means
that 100% of labor and materials are from the United States. Let p represent
the true proportion of consumers who believe “Made in the USA” means 100% of
labor and materials are from the United States.
a.Calculate
a point estimate for p.
b. A claim
is made that p is 0.30. Set up the null and alternative hypotheses .
c.
Calculate
the test statistic for the test, part b.
d. Find the
rejection region for the test if a=0.10.
e. Make the
appropriate conclusion.
7. Independent
random samples from approximately normal populations produced the results shown
below.a. Do the
data present sufficient evidence to conclude that mean 1-mean 2?0? Use a =0.01.
Find
the test statistic.
Find
the p-value.
Choose
the correct conclusion below.
b.
Construct
a 99% confidence interval for (mean1-mean2).
8.
The data
for a random sample of six paired observations are shown in the table.a. Calculate
d and s_d^2.
b. What is
the 90% confidence interval for mean d?
c.
What is
the appropriate conclusion of the hypothesis test at a=0.10?
9.
Construct
a 95% confidence interval for (p1-p2) in each of the following
situations.
a.
n 1 =400,
p 1 =0.66, n 2 =400, p 2 = 0.57.
b.
n 1 =180, p 1 =0.31, n 2 = 250, p 2 =0.27.
c. n 1
=100, p 1 =0.47, n 2 =120, p 2 =0.59.
10. A
newspaper reported the results of a survey on the planning habits of men and
women . In response to a question “What is your preferred method of keeping
track of meetings?” 55 of men and 45 of women answered “I keep them in my
head”. A nationally representative sample of 1,000 adults participated in
the survey; therefore, assume that 500 were men and 500 were women.
a. Set up
the null and alternative hypotheses for testing whether the percentage of men
who prefer keeping track of appointments in their head, p1, is larger than the
corresponding percentage of women, p2.
b.
Compute the test statistic for the test.
c. Give
the rejection region for the test, using a=0.01.
d. Find
the p-value for the test.
e. Make
an appropriate conclusion.

11. An auto dealer researching
customer preferences for cars asks customers which colors they prefer in a car
from a choice of red, yellow, black, and white. The data being collected can be
categorized as

12. Which of the following choices determines the
extent to which a measuring instrument measures what the researcher sets out to
measure?

13. Which
type of scale consists of statements that express either a favorable or
unfavorable attitude toward an object of interest?

14. The
assignment of numbers or symbols to a property of objects according to value or
magnitude is called

15. Rachel is conducting a
telephone interviews for Blockbuster. When she interviews customers of Netflix
she tends to change the wording of the question “How loyal are you to using
Blockbuster” to “So, you aren’t loyal to Blockbuster, are you”. Which of the
following sources of error in communication research is present in this
example?

16. Every
time a Netflix customer returns a DVD, Netflix asks the customer to evaluate
the DVD relative to other DVDs on a scale from one to five. Netflix is
using… question to learn customer preferences.

17. When
target questions present the participants with a fixed set of choices, they are