Atividade - Statistics 4

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 Pergunta 1 
1 em 1 pontos 
 
 Skill: Carry out the hypothesis test for the population mean and draw conclusions in context 
"multiple choice" question: select the correct answer. Which of the following is true regarding the t-
distribution. 
 
Resposta Selecionada: 
All of the above are correct. 
Resposta Correta: 
All of the above are correct. 
Feedback da resposta: This is correct. 
 
 
 Pergunta 2 
0 em 1 pontos 
 
 The Medical College Admission Test (MCAT) is an examination for prospective medical 
students.Suppose that based on data collected from a random sample of 100 MCAT takers, the 95% 
confidence interval for μ, the mean MCAT score, was calculated to be (497, 503). 
Skills: 
Calculate interpret the confidence interval for the population mean , and recognize the effect of level 
of confidence and sample size on the precision of the interval estimation. Calculate interpret the 
confidence interval for the population proportion p, and recognize the effect of level of confidence 
and sample size on the precision of the interval estimation. 
"multiple choice" question: select the correct answer. 
What is the margin of error of this confidence interval? 
 
Resposta Selecionada: 
5% 
Resposta Correta: 
3 
 
 
 Pergunta 3 
1 em 1 pontos 
 
 A random sample of 700 U.S. adults was asked the following question:Do you approve or disapprove 
of the way Donald Trump is handling his job as president?280 of the 700 responded that they 
approve. 
Skill: Calculate interpret the confidence interval for the population proportion p, and recognize the 
effect of level of confidence and sample size on the precision of the interval estimation. 
"multiple choice" question: select the correct answer. Which of the following is the correct 90% 
confidence interval for p, the proportion of all U.S. adults who approve of the way Donald Trump is 
handling his job as president?(Answers are rounded to two decimal places). 
 
Resposta Selecionada: 
(0.37, 0.43) 
Resposta Correta: 
(0.37, 0.43) 
 
Feedback da 
resposta: 
This is correct. 
ρˆ±1.645⋅ρˆ(1−ρˆn−−−−−√=.40±1.645⋅.40(.60)700−−−−−√≈.40±.03=(.37, .43) 
 
 Pergunta 4 
1 em 1 pontos 
 
 Skill: Carry out the hypothesis test for the population mean and draw conclusions in context 
"multiple choice" question: select the correct answer. The p-value of the test is 0.022. Which of the 
following is the appropriate conclusion at the 5% significance level? 
 
Resposta 
Selecionada: 
 
The data provide evidence to reject H0 and conclude that the mean volume 
dispensed is not the required 752ml. 
Resposta Correta: 
The data provide evidence to reject H0 and conclude that the mean volume 
dispensed is not the required 752ml. 
Feedback da resposta: This is correct. 
 
 
 Pergunta 5 
1 em 1 pontos 
 
 A large insurance company wanted to estimate μ, the mean claim size (in $) on an auto insurance 
policy. A random sample of 225 claims was chosen and it was found that the average claim size was 
$2875. From past experience the population standard deviation is assumed to be $1350. 
Skill: Calculate interpret the confidence interval for the population mean , and recognize the effect of 
level of confidence and sample size on the precision of the interval estimation. 
"multiple choice" question: select the correct answer. Which of the following is the 95% confidence 
interval for μ? 
 
Resposta Selecionada: 
(2695, 3055) 
Resposta Correta: 
(2695, 3055) 
Feedback da 
resposta: 
This is correct. The 95% confidence interval is: 
x¯±2⋅σn√=2875±2⋅1350225√=2875±180=(2695, 3055) 
 
 
 Pergunta 6 
1 em 1 pontos 
 
 Wineries use machines that automatically fill the bottles. The amount of wine that the machine 
dispenses will naturally vary slightly from bottle to bottle. To determine whether the machine is 
working properly, bottles are occasionally sampled and the volume of wine is measured. A winery in 
California randomly sampled 5 bottles and found that the average volume in these bottles was 747.6 
milliliters (ml). If the machine is working properly, bottles should contain 752 ml of wine, on 
average. Using the data they collected, the winery would like to test whether μ, the mean volume 
dispensed by the machine differs from this value (752 ml). Suppose that the volume of wine 
dispensed by the machine is known to have a normal distribution with standard deviation σ=4.3 ml. 
 
 
 
Skill: Carry out the hypothesis test for the population mean and draw conclusions in context 
"multiple choice" question: select the correct answer. Which of the following are the correct null and 
alternative hypotheses in this case? 
Resposta Selecionada: 
H0: μ=752 ; Ha: μ≠752 
Resposta Correta: 
H0: μ=752 ; Ha: μ≠752 
Feedback da resposta: This is correct. 
 
 
 Pergunta 7 
0 em 1 pontos 
 
 The question whether birth order affects juvenile delinquency was examined in a large study using a 
high school population. A random sample of 1,060 boys attending public school were given a 
questionnaire that measured delinquent behavior and then classified each boy as either 'Yes' or 'No'. 
Each boy also indicated his birth order: the oldest, in between, or the youngest. The results are 
summarized in the following two-way table: 
 
 
Resposta Selecionada: 
birth order and delinquent behavior are not independent. 
Resposta Correta: 
birth order and delinquent behavior are independent. 
 
 
 Pergunta 8 
0 em 1 pontos 
 
 Skill: Perform inference for the linear relationship between two quantitative variables 
"multiple choice" question: select the correct answer. The observed relationship in the scatterplot 
means that: 
 
Resposta 
Selecionada: 
 
The higher IQ of a child is the cause for lower risk of delinquent behavior. 
 
Resposta Correta: 
The more intelligent the child is (as measured by IQ) the lower the risk of 
delinquent behavior. 
Feedback da resposta: This is correct. 
 
 Pergunta 9 
1 em 1 pontos 
 
 The question whether birth order affects juvenile delinquency was examined in a large study using a 
high school population. A random sample of 1,060 boys attending public school were given a 
questionnaire that measured delinquent behavior and then classified each boy as either 'Yes' or 'No'. 
Each boy also indicated his birth order: the oldest, in between, or the youngest. The results are 
summarized in the following two-way table: 
 
To test whether the data provides significant evidence for a relationship between birth order and 
delinquent behavior, we will use the Chi-square test for independence. 
Skill: Carry out the chi-square test for the independence of two categorical variables and draw 
meaningful conclusions. 
"Fill in the blank" question: select the correct answer. Complete the following sentences:The 
appropriate hypotheses in this case are: 
 
Resposta Selecionada: 
 There is no relationship. 
Resposta Correta: 
 There is no relationship. 
Feedback da resposta: This is correct. 
 
 
 Pergunta 10 
1 em 1 pontos 
 
 Skill: Carry out the ANOVA procedure or comparing more than two population means. 
"multiple choice" question: select the correct answer. The analysis was run on the data and the 
following output was obtained: 
 
Which of the following is the correct interpretation of the P-value in the context of this study? 
 
Resposta 
Selecionada: 
 
The probability of getting data like that observed in the study (or more extreme) if 
performance on the SAT-Math is not related to the the study strategy. 
Resposta 
Correta: 
 
The probability of getting data like that observed in the study (or more extreme) if 
performance on the SAT-Math is not related to the the study strategy. 
Feedback da resposta: This is correct.