Assignment: 8-1 MyStatLab: Module: Statistic

Assignment: 8-1 MyStatLab: Module: Statistic

Eight Homework
1: Data Table
(1) Fail to reject
Reject
(2) insufficient
sufficient
A subtle form of racial discrimination in housing is “racial steering.” Racial steering occurs when real estate agents
show prospective buyers only homes in neighborhoods already dominated by that family’s race. Tenants at a large
apartment complex recently filed a lawsuit alleging racial steering. The plaintiffs claimed that potential renters
were steered to Section A, while African-American renters were steered to Section B. The accompanying table displays
the data that were presented in court to show the locations of recently rented apartments. Do you think there is
evidence of racial steering?
white
Click the icon to view the data table showing locations of recently rented apartments. 1
State the null and alternative hypotheses. Choose the correct answer below.
A. H : There is an association between race and the section of the apartment complex. 0
H : There is no association between race and the section of the apartment complex. A
B. H : There is no association between race and the section of the apartment complex. 0
H : There is an association between race and the section of the apartment complex. A
C. H : More s rent in section A. 0 white
H : More African-Americans rent in section B. A
D. H : More African-Americans rent in section A. 0
H : More s rent in section B. A white
Find the ? statistic. 2
? (Round to three decimal places as needed.) 2 =
Find the P-value.
P-value = (Round to four decimal places as needed.)
State your conclusion at the significance level a = 0.05.
(1) . There is (2) evidence to conclude that there is an association between race
and the section of the apartment complex in which people live.
H0
Data table showing locations of recently rented apartments
White African-American Total
Section A 85 7 92
Section B 82 22 104
Total 167 29 196
2. Newspaper headlines at the time and traditional wisdom in the succeeding
decades have held that women and children escaped a sunken ship in greater
proportion than men. Here’s a table with the relevant data. Do you think that
survival was independent of whether the person was male or female? Defend your
conclusion.
Female Male Total
Alive 374 276 650
Dead 123 1363 1486
Total 497 1639 2136
Is there evidence of a significant difference between the proportion of males and females who survived at the
0.025 level of significance? What are the null and alternative hypotheses to test?
A. H : Survival was independent of gender on the ship. 0
H : There is an association between survival and gender on the ship. A
B. H : Survival was dependent on gender on the ship. 0
H : There is no association between survival and gender on the ship. A
C. H : There is an association between survival and gender on the ship. 0
H : Survival was independent of gender on the ship. A
D. H : There is no associations between survival and gender on the ship. 0
H : Survival was dependent on gender on the ship. A
Are the conditions for inference satisfied?
A. Yes, because the data are in counts, the data in groups are dependent on each other, and the groups
are sufficiently large.
B. Yes, because the data are counts, the data in groups are independent, and the groups have at least 5
observations.
C. No, because the data are not in counts, the data in groups are independent, and there is at least one
group that has less than 5 observations.
D. No, because the data are in counts, the data in the groups are dependent on each other, and the
groups have at least 5 observations.
Calculate the test statistic.
? (Round to two decimal places as needed.) 2 =
Determine the p-value and interpret its meaning.
The p-value is . (Round to three decimal places as needed.)
Interpret the p-value. Choose the correct answer below.
A. Fail to reject the null hypothesis and conclude there is weak evidence of an association between
survival and gender on the ship. Both genders were equally likely to survive.
B. Fail to reject the null hypothesis and conclude there is strong evidence of an association between
survival and gender on the ship. Females were more likely to survive.
C. Reject the null hypothesis and conclude there is strong evidence of an association between survival
and gender on the ship. Females were more likely to survive.
D. Reject the null hypothesis and conclude there is weak evidence of an association between survival and
gender on the ship. Both genders were equally likely to survive.
3.
4.
2: Survey Results
(1) greater than
less than
(2) not sufficient
sufficient
(3) independent
not independent
A polling institute routinely conducts surveys to gauge the impact of the Internet and technology on daily life. A recent
survey asked respondents if they read online journals or blogs, an Internet activity of potential interest to many
businesses. A subset of the data from this survey shows responses to this question. Test whether reading online
journals or blogs is independent of generation. Use a significance level of a = 0.05.
Click the icon to view the data from the survey. 2
Determine the null and alternative hypotheses. Choose the correct answer below.
A. H : Generation and online journal or blog reading are independent. 0
H : Generation and online journal or blog reading are not independent. A
B. H : Generation and online journal or blog reading are not independent. 0
H : Generation and online journal or blog reading are independent. A
C. H : The distribution of responses is the same for all generations. 0
H : The distribution of responses is not the same for all generations. A
D. H : The distribution of responses is not the same for all generations. 0
H : The distribution of responses is the same for all generations. A
Compute the ? test statistic. 2
? (Round to two decimal places as needed.) 2 =
Find the P-value.
P-value = (Round to three decimal places as needed.)
What do you conclude? Choose the correct answer below.
The P-value is (1) the significance level. There is (2) evidence to reject the null
hypothesis. Thus, the test concludes that reading online journals or blogs is (3) of generational age.
Read Online Journal or Blog
Yes, Yesterday
Yes, But Not
Yesterday No Total
Generation
Gen-Y (18-30) 27 36 64 127
Gen-X (31-42) 15 36 143 194
Trailing Boomers
(43-52) 15 33 126 174
Leading Boomers
(53-61) 9 22 88 119
Matures (62+) 9 24 104 137
Total 75 151 525 751
It has become more common for shoppers to “comparison shop” using the Internet. Respondents to a survey in 2013
who owned cell phones were asked whether they had, in the past 30 days, looked up the price of a product while they
3: More Info
were in a store to see if they could get a better price somewhere else. Here is a table of their responses by income
level. Complete parts a) and b) below.
Click the icon to view the table. 3
a) Is the frequency of comparison shopping of comparison shopping on the Internet independent of the income level of
the income level of the respondent? Perform an appropriate chi-square test and state your conclusion. State the null
and alternative hypotheses for testing whether income level and cybershopping are related. Choose the correct answer
below.
A. H : Income level and cybershopping are independent. 0
H : Income level and cybershopping are not independent. A
B. H : Income level and cybershopping are not independent. 0
H : Income level and cybershopping are independent. A
C. H : A person with a high income level is more likely to cybershop. 0
H : A person with a high income level is less likely to cybershop. A
D. H : A person with a high income level is less likely to cybershop. 0
H : A person with a high income level is more likely to cybershop. A
Compute the ? statistic. 2
? (Round to two decimal places as needed.) 2 =
State the appropriate conclusions about the hypotheses. Choose the correct answer below.
A. Fail to reject the null hypothesis. Income level and cybershopping are independent.
B. Reject the null hypothesis. Income level and cybershopping are independent.
C. Fail to reject the null hypothesis. Income level and cybershopping are not independent.
D. Reject the null hypothesis. Income level and cybershopping are not independent.
b) Calculate and examine the standardized residuals. What pattern, if any, do they show that would be of interest to
retailers concerned about cybershopping comparisons? Complete the table below.
< $30 $30-$49.9 $49.9-$74.9 > $75
Yes
No
(Round to five decimal places as needed.)
What pattern is shown?
A. Shoppers are less likely to cybershop for comparison prices if they earn more money.
B. Shoppers are more likely to cybershop for comparison prices if they earn more money.
C. Cybershopping is the best form of comparison shopping for people who earn less money.
D. Cybershopping is the best form of comparison shopping for people who earn more money.
< $30K $30K?$49.9K $50K?$74.9K > $75K
Yes 177 93 166 152
No 650 395 235 404
5. In a recent study of enterprise resource planning (ERP) system effectiveness, researchers asked companies how they
assessed the success of their ERP systems. Out of manufacturing companies surveyed, they found that used
return on investment (ROI), used reductions in inventory levels, used improved data quality, and used
on-time delivery. In a survey of service firms, used ROI, used inventory levels, used improved data
quality, and used on-time delivery. Is there evidence that the measures used to assess ERP system effectiveness
differ between service and manufacturing firms? Perform the appropriate test and state your conclusion.
375 182
140 42 11
250 50 60 110
30
State the null and alternative hypothesis. Choose the correct answer below.
A. H : There is no pattern in the assessment method by industry sectors. 0
H : There is a pattern in the assessment method by industry sectors. A
B. H : The method of assessment is independent of industry sector. 0
H : There is an association between assessment method and industry sector. A
C. H : The proportions of assessment method are the same for each industry sector. 0
H : The proportion of assessment method is different for at least one industry sector. A
Determine the ? statistic. 2
? (Round to three decimal places as needed.) 2 =
Find the P-value.
P-value = (Round to four decimal places as needed.)
State your conclusion at the significance level a = 0.05. Choose the correct answer below.
A. . There is evidence that there is an association between the method used to assess
the ERP systems and the type of industry.
Reject H0 sufficient
B. . There is evidence that the proportion of assessment method is different for at least
one industry sector.
Reject H0 sufficient
C. . There is evidence that there is a pattern to assessment method by industry
sector.
Fail to reject H0 insufficient
D. . There is evidence that there is an association between the method used to
assess the ERP systems and the type of industry.
Fail to reject H0 insufficient
6.
4: GDP % Change Table
(1) Fail to reject
Reject
(2) is
is not
(3) is not independent of region.
increases from west to east.
increases from east to west.
is independent of region.
A government’s economic analysis branch recently released figures that they claimed showed a growth spurt in the
western region of a certain country that is divided into states. Using the accompanying table, where the cell values
are numbers of states, determine if the percent change in real GDP by state was independent of region of the country.
Use .
51
a = 0.05
Click the icon to view the data table. 4
What are the null and alternative hypotheses?
A. H : GDP % change is independent of region. 0
H : GDP % change increases from west to east. A
B. H : GDP % change is independent of region. 0
H : GDP % change is not independent of region. A
C. H : GDP % change is not independent of region. 0
H : GDP % change is independent of region. A
D. H : GDP % change is independent of region. 0
H : GDP % change increases from east to west. A
What is the test statistic?
? (Round to two decimal places as needed.) 2 = 10.68
What is the P-value?
P-value = (Round to three decimal places as needed.)
What is the proper conclusion?
(1) . There (2) sufficient evidence to conclude that GDP % change
(3)
H0
GDP %Change
Region Top 40% Bottom 60% Total
West 12 3 15
Midwest 4 8 12
Southeast 3 9 12
Northeast 2 10 12
Total 21 30 51