QNT 561 Week 4 Quiz

QNT 561 Week 4 Quiz

1.
A new type of screening for lung cancer ,
CT, has been developed. Medical researchers believe that CT scans are more
sensitive than regular X-rays in pinpointing small tumors. A university is
conducting a medical trial of 50,000 smokers nationwide to compare the
effectiveness of CT scans with X-rays
for detecting lung cancer… One goal of the study is to compare the mean
ages when cancer is first detected by
the two screening methods.
2.
A study of Machiavellian traits in
consultants was performed… The consultants were then classified as having dishonest, neutral, or honest Mach
rating scores. The researcher investigated the impact of both Mach score and
gender on the average income of a consultant.

3.
Consider the dot plots A and B.
Plot A: Sample 1:
6,7,8,8,9,10 Sample 2:
12,13,14,14,15,16
Plot B: Sample 1: 5,5,7,11,13,13 Sample 2: 10,12,12,16,16,18

Plot A:4.
The partially completed ANOVA table for a 3×4 factorial experiment with two
replications is shown below:5.
The table for problem 5 was missing, so we
didn’t have to complete problem 5.

6.
What conditions must n satisfy to make the
x^2 test valid?
n must be large enough so that for every cell the
expected cell count will be equal to 5 or more.
7.
The table to the right gives the breakdown
of the root causes of a sample of 87 industrial accidents. Are there
significant differences in the percentage of incidents in the four cause
categories? Use a=0.05.Determine the null and alternative hypothesis for this
test.
Ho_p1=p2=p3=p4=0.25

8.
Find the rejection region for a test of
independence of two classifications
where the contingency table contains r rows and c columns.
a.
a=0.05, r=3, c=6
b.
a=0.10, r=6, c=3.
c.
a=0.01, r=2, c=5.

9.
Test the null hypothesis of independence
of the two classifications A and B of accompanying contingency table. Use
a=0.05.Specify the null and alternative hypothesis.
Ho: The row and column classifications are
independent.
Ha: The row and column classifications are dependent.
Find the test statistics.
X^2=10.57.
Specify the rejection region.
X^2>9.48773.
State the conclusion.
Reject Ho; there is sufficient evidence to indicate
the row and column classification are dependent at a=0.05.

10.
Which term below refers to the descriptors
of variables computed from sample data used to estimate those same variables in
the population?
Sample statistics.
11.
Which term below refers to a controlled,
randomized procedure that assures that each population element is given a
known, nonzero chance of selection into a study’s sample?
Probability sampling.
12.
When selecting a convenience sample ,
element selection is based on.
Accessibility.
13.
Involves assigning numbers or other
symbols to answers so that the responses can be grouped into a limited number
of categories.
Coding.
14.
Which type of chart uses bars to represent
data values such that each value occupies an equal amount of area within an
enclosed area?
Histogram.