1.
Quiz format- Randomly questions from Chptr 7-9, will add chpt 10
2.
construct the 95% confidence interval for estimating, the population mean
X= 5.2
s=0.7
N=157
3.
Construct the 95% confidence interval for estimating , the population mean
X=33
S=6
N=220
4.
A researcher has gathered information from a random sample of 178 households. For each variable below, construct confidence intervals to estimate the population mean. Use the 90% level
The households averaged 6.0 hours of television viewing per day (s 3.0).
5.
A random sample of 429 college students was interviewed about a number of matters.
On average, the sample had missed 2.8 days of classes per semester because of illness. If the sample standard deviation is 1.0, construct an estimate of the population mean at the 99% level.
6.
A random sample of 1,496 respondents of a major metropolitan area was questioned about a number of issues. Construct estimates to the population at the 90% level for each of the results reported below. Express the final confidence interval in percentages
375 of the sample agreed that marijuana should be legalized.
7.
Random sample of 1,496 respondents of a major metropolitan area was questioned about a number of issues. Construct estimates to the population at the 90% level for each of the results reported below. Express the final confidence interval in percentages (e.g., between 40 and 45% agreed that premarital sex was always wrong).
800 agreed that public elementary schools should have sex education programs starting in the fi fth grade
8.
The fraternities and sororities at St. Algebra College have been plagued by declining membership over the past several years and want to know if the incoming freshman class will be a fertile recruiting ground. Not having enough money to survey all 1,600 freshmen, they commission you to survey the interests of a random sample. You find that 35 of your 150 respondents are extremely interested in social clubs. At the 95% level, what is your estimate of the number of freshmen who would be extremely interested?
A.
240 (15%) and 496 (31%) of the 1,600 freshmen
B.
440 (45%) and 506 (51%) of the 1,600 freshmen
C.
90 (5%) and 1410 (95%) of the 1,600 freshmen
D.
9.
Nationally, social workers average 10.2 years of experience. In a random sample, 203 social workers in greater metropolitan Shinbone average only 8.7 years with a standard deviation of 0.52. Are social workers in Shinbone significantly less experienced?
A.
. Z (obtained) −41.00- not significant- we fail to reject the null
B.
. Z (obtained) −41.00- we failed to accept the null hypothesis- it is significant
C.
. Z (obtained) −33.00- it is significant, we reject the null hypothesis
D.
. Z (obtained) −33.00- it is insignificant, we reject the null hypothesis
E.
. Z (obtained) 41.00- it is significant, we reject the null hypothesis
10.
Random sample of 423 Chinese Americans has finished an average of 12.7 years of formal education with a standard deviation of 1.7. Is this significantly different from the national average of 12.2 years?
A.
Z (obtained) -3.04- significant
B.
Z (obtained) 1.04- insignificant
C.
Z (obtained) 3.01- insignificant
D.
Z (obtained) 6.04- significant
11.
A survey shows that 10% of the population is victimized by property crime each year. A random sample of 527 older citizens (65 years or more of age) shows a victimization rate of 14%. Are older people more likely to be victimized?
A.
Z (obtained) 3.06- significant
B.
Z (obtained) 1.5- insignifcant
C.
Z (obtained) 4.78- insignificant
D.
Z (obtained) -6.4- signifcant
12.
A researcher has compiled a file of information on a random sample of 317 families in a city that has chronic, long-term patterns of child abuse. Below are reported some of the characteristics of the sample along with values for the city as a whole. For each trait, test the null hypothesis of “no difference” and summarize your findings.
Mothers’ educational level (proportion completing high school): City Sample Pu = 0.63 Ps = 0.61
13.
Do athletes in different sports vary in terms of intelligence? Below are reported College Board scores of random samples of college basketball and football players. Is there a significant difference? Write a sentence or two explaining the difference.
X —1 = 452 X —2 = 480 s1 = 88 s2 = 75 N1 = 107 N2 = 105
A.
Alpha= 11.28, Z (obtained) −2.48- significant reject the null hypothesis
B.
B. 11.28, Z (obtained) −2.48- not significant we fail to reject the null hypothesis
14.
Are senior citizens who live in retirement communities more socially active than those who live in age-integrated communities? Write a sentence or two explaining the results of these tests.
A random sample of senior citizens living in a retirement village reported that they had an average of 1.42 face-to-face interactions per day with their neighbors. A random sample of those living in age-integrated communities reported 1.58 interactions. Is the difference significant?
N1=43 N2=37
S=0.10 0.37
15.
About half of the police officers in Shinbone, Kansas, have completed a special course in investigative procedures. Has the course increased their efficiency in clearing crimes by arrest? The proportions of cases cleared by arrest for samples of trained and untrained officers are reported below.
P s 1 = 0.47 P s 2 = 0.43 N1 = 157 N2 = 113
A.
Pu 0.45, Z (obtained) 0.67
B.
Pu 0.67 Z (obtained) 0.45,
16.
Some results from a survey administered to a nationally representative sample are presented below. For each table, conduct the chi square test of significance and compute column percentages. Write a sentence or two of interpretation for each test.
Support for the legal right to an abortion for any reason by age:
Yes 154 360 213
No 179 441 429
Some results from a survey administered to a nationally representative sample are presented below. For each table, conduct the chi square test of significance and compute column percentages. Write a sentence or two of interpretation for each test.
Support for the legal right to an abortion for any reason by age:
Totals
Yes 154 360 213 727
No 179 441 429 1049
Totals 333 801 642 1776
A.
25.19, Yes ,The oldest age group was most opposed
B.
33. 07, No, The youngest group supported most
C.
17. 76, Yes, all equally apposed
D.
19. 69- No, Oldest age group supported the most
17.
The state department of education has rated a sample of local school systems for compliance with state-mandated guidelines for quality. Is the quality of a school system significantly related to the affluence of the community as measured by per capita income?
Low 16 8 24
High 9 17 26
Totals 25 25 50
A.
The obtained chi square is 3.149. which is significant (df 1, alpha 0.05), column percentages show
B.
None of the above are corrrect
C.
The obtained chi square is 5.12, which is significant (df 1, alpha 0.05). The column percentages show that more affluent communities have higher quality schools.
D.
The obtained chi square is 1.168, which is not significant at (df 1, alpha 0.05). The column percentages show that more affluent communities have higher quality schools.
18.
ANOVA has been left out as the PDF answers wrong