Quiz__Practice_Exam_2a_-_Highly_Recommended_but_Optional_42_Questions

pdf

School

California State University, Fullerton *

*We aren’t endorsed by this school

Course

301

Subject

Statistics

Date

Apr 3, 2024

Type

pdf

Pages

Uploaded by BaronComputer3787

10/12/22, 7:43 PM Quiz: Practice Exam 2a - Highly Recommended but Optional (42 Questions) https://csufullerton.instructure.com/courses/3331590/quizzes/8290372/take?preview=1 1/19 Practice Exam 2a - Highly Recommended but Optional (42 Questions)  This is a preview of the published version of the quiz Started: Oct 12 at 7:43pm Quiz Instructions The following 5 questions are based on this information. Suppose a random sample of 18 uber drivers was taken, and the average age x̄ of these drivers was found to be 27.5 years. Construct a 99% confidence interval for the mean age (µ) of all drivers. Assume that the age of drivers is normally distributed with a population standard deviation (σ) of 2.3 years. 1 pts Question 1 0.54 6.48 2.3 0.13 The standard error (SE) of x̄ is 1 pts Question 2

10/12/22, 7:43 PM Quiz: Practice Exam 2a - Highly Recommended but Optional (42 Questions) https://csufullerton.instructure.com/courses/3331590/quizzes/8290372/take?preview=1 2/19 0.005 2.58 0.01 2.32 The critical value (CV) used for a 99% interval estimate is 1 pts Question 3 27.5 ± 0.54 27.5 ± 1.26 27.5 ± 1.39 27.5 ± 2.3 The 99% confidence interval estimate of µ is 1 pts Question 4 Your claim is not statistically justified Your claim is statistically justified The company claims that average age of drivers is 26.9 years. In light of the sample evidence and at the 1% level of significance,

10/12/22, 7:43 PM Quiz: Practice Exam 2a - Highly Recommended but Optional (42 Questions) https://csufullerton.instructure.com/courses/3331590/quizzes/8290372/take?preview=1 3/19 1 pts Question 5 stays the same decrease increase be zero If we decrease the confidence level (1-α) from 0.99 to 0.95, the margin of error (ME) of the confidence interval estimate will The following 6 questions are based on this information. A large cycle company reported that in 2010, 65% of parents of children (between the ages of 8 to 12), bought their children a cycle. That same company has stated that cycle purchases for that same age group have gone up. They surveyed 300 parents of children and found that 230 of them have bought cycle to their children. 1 pts Question 6 H(0): p≤0.65 Versus H(a): p>0.65 H(0): p≥0.65 Versus H(a): p<0.65 Specify the null and alternative hypotheses. 1 pts Question 7

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

10/12/22, 7:43 PM Quiz: Practice Exam 2a - Highly Recommended but Optional (42 Questions) https://csufullerton.instructure.com/courses/3331590/quizzes/8290372/take?preview=1 4/19 0.058 0.037 0.028 0.047 The standard error (SE) of p¯ is The following 5 questions are based on this information. In 2017, it was reported that women sent on average 3,000 texts per month. It is believed that the number of texts sent has increased. In fact, a recent random sample of 60 women showed that they send an average 3,500 texts per month( ) with a sample standard deviation of 600 texts ( ). Assume that the random variable, number of texts sent by women(denoted by X ), is normally distributed. Is this sufficient statistical evidence to show that women are now sending on average more than 3000 texts per month? X¯=3,500 texts s=600 texts 1 pts Question 8 H(0): μ≤3,000 versus H(a): μ>3,000 H(0): μ≥3,000 versus H(a): μ<3,000 Specify the null and alternative hypotheses. 1 pts Question 9

10/12/22, 7:43 PM Quiz: Practice Exam 2a - Highly Recommended but Optional (42 Questions) https://csufullerton.instructure.com/courses/3331590/quizzes/8290372/take?preview=1 5/19 77.45 3.01 0.24 0.76 The standard error (SE) of x̄ is 1 pts Question 10 6.45 2.08 0.66 0.53 The test statistics value is 1 pts Question 11 0.999 0.301 0.000 0.973 The p-value is

10/12/22, 7:43 PM Quiz: Practice Exam 2a - Highly Recommended but Optional (42 Questions) https://csufullerton.instructure.com/courses/3331590/quizzes/8290372/take?preview=1 6/19 1 pts Question 12 We reject H(0) in favor of H(a) We do not reject H(0) At α=0.01 and using the p-value The following 5 questions are based on this information. Historically, the average number of boats owned by the people living in the coasts in a lifetime has been 12. An economist believes that the number is now lower because of recent economic downturns. A recent survey of 30 senior citizens indicates that the average number of boats owned over their lifetime is 10. Assume that the random variable, number of boats owned in a lifetime (denoted by X), is normally distributed with a standard deviation (σ) is 4.5. 1 pts Question 13 H(0): μ≥12 versus H(a): μ<12 H(0): μ≤12 versus H(a): μ>12 Specify the null and alternative hypotheses. 1 pts Question 14 The standard error (SE) of x̄ is

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

10/12/22, 7:43 PM Quiz: Practice Exam 2a - Highly Recommended but Optional (42 Questions) https://csufullerton.instructure.com/courses/3331590/quizzes/8290372/take?preview=1 7/19 10.5 0.82 2.5 4.5 1 pts Question 15 0.00 0.05 0.99 0.03 The p-value is 1 pts Question 16 -2.5 2.5 -2.43 0.9 The test statistics value is 1 pts Question 17

10/12/22, 7:43 PM Quiz: Practice Exam 2a - Highly Recommended but Optional (42 Questions) https://csufullerton.instructure.com/courses/3331590/quizzes/8290372/take?preview=1 8/19 We reject H(0) in favor of H(a) We do not reject H(0) At α=0.10 and using the p-value The following 5 questions are based on this information. In a poll of 500 Graduate students, .75% (p¯=0.75) said that they used only Internet for the project and assignment purposes.. The goal is to construct a 99% confidence interval for the percentage (p) of Graduate students who use the Internet for project and assignment purposes. 1 pts Question 18 0.0004 0.0002 0.016 0.019 The standard error (SE) of is p¯ 1 pts Question 19 2.58 The critical value (CV) needed for 99% confidence interval estimation is

10/12/22, 7:43 PM Quiz: Practice Exam 2a - Highly Recommended but Optional (42 Questions) https://csufullerton.instructure.com/courses/3331590/quizzes/8290372/take?preview=1 9/19 1.96 1.64 1.28 1 pts Question 20 0.75 ± 0.15 0.75 ± 0.05 0.44 ± 0.03 0.44 ± 0.002 The 99% confidence interval estimate of p is 1 pts Question 21 We cannot reject the Dean's claim We can reject the Dean's claim Suppose around the period the above poll was conducted,The DEan of a university made a personal statement saying that .85% of Graduate students used only the Internet for assignment purposes In light of the sample evidence and at the 1% level of significance, 1 pts Question 22

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

10/12/22, 7:43 PM Quiz: Practice Exam 2a - Highly Recommended but Optional (42 Questions) https://csufullerton.instructure.com/courses/3331590/quizzes/8290372/take?preview=1 10/19 250 125 500 73 A Dean of the universityl wishes to collect new random sample with the aim of building a new confidence interval at the 99% confidence level for p. Using the current sample proportion (from the 500 graduate students poll ) as a basis, what sample size (n) would the journalist require to achieve a 10% margin of error? The following 5 questions are based on this information. A survey indicates that the proportion of girls in the total youth in the United States is 51% (p=0.51). We will take a random sample of 400 U.S. youths. 1 pts Question 23 is not normal because the sample size is too small is normal because np≥5 and n(1−p)≥5 is normal because the only requirement is for n to be greater than 30 and that is met The sampling distribution of p¯, the sample proportion of U.S.youths who are girls, is:

10/12/22, 7:43 PM Quiz: Practice Exam 2a - Highly Recommended but Optional (42 Questions) https://csufullerton.instructure.com/courses/3331590/quizzes/8290372/take?preview=1 11/19 is not normal because n < 500 1 pts Question 24 0.025 0.038 0.006 0.001 The standard error (SE) of p¯ is 1 pts Question 25 43% 76.99 23% 57% What is the probability that a random sample of 400 U.S. youth will provide a sample proportion (p¯) that is within 0.03 of the population proportion (p)? 1 pts Question 26 99% What is the probability (rounded) that a random sample of 400 U.S youth will provide a sample proportion (p¯) that is within 0.07 of the population proportion (p)?

10/12/22, 7:43 PM Quiz: Practice Exam 2a - Highly Recommended but Optional (42 Questions) https://csufullerton.instructure.com/courses/3331590/quizzes/8290372/take?preview=1 12/19 2% 1% 89% 1 pts Question 27 This is NOT a rare finding because the likelihood of p¯ =0.42 is quite large as we saw in the previous question This is a rare finding because the likelihood of \p¯=0.42 is quite small as we saw in the previous question Say, you took a random sample of 400 U.S. youth, and found out that the sample proportion ( p¯) for this sample to be 0.42. The following 6 questions are based on this information. According to a journalist of BBC News from April 2016, the average price of milk at all U.S. supermarkets was $3.00 (µ). The population standard deviation (σ) of milk prices is $1.75. Let X be a random variable denoting milk price at super market. We plan to take a random sample of 36 supermarkets. 1 pts Question 28 Is normal due to the Chebyshev’s Theorem Is not normal because the sample size is too small What is the sampling distribution of x̄ when sample of size 36 is used?

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

10/12/22, 7:43 PM Quiz: Practice Exam 2a - Highly Recommended but Optional (42 Questions) https://csufullerton.instructure.com/courses/3331590/quizzes/8290372/take?preview=1 13/19 Is normal due to the Central Limit Theorem Is not normal because the sample size is too large 1 pts Question 29 X has a skewed distribution X has a bi-modal distribution X has a normal distribution X has a uniform distribution Suppose that we reduce the sample size from 36 to 16. The sampling distribution of x̄ will be normal only if 1 pts Question 30 31% 9% 45.5% 4.3% What is the probability that a random sample of 36 supermarkets will provide an average milk price (x̄ ) that is more than $3.50? 1 pts Question 31

10/12/22, 7:43 PM Quiz: Practice Exam 2a - Highly Recommended but Optional (42 Questions) https://csufullerton.instructure.com/courses/3331590/quizzes/8290372/take?preview=1 14/19 9% 38% 62% 91% What is the probability that a random sample of 36 supermarkets will provide an average milk price (x̄ ) that is within $0.50 of the population mean ( μ)? 1 pts Question 32 stay the same increase be zero decrease The probability in the PREVIOUS question would _________if we were to increase the sample size to 72. Use this information to answer the following 6 questions:: The U.S. Police department wants to know if a new campaign, to make citizens aware of the dangers of drunk driving, has been effective. They count the number of drivers who have been stopped with more alcohol in their body than the law permits for each day of the week in the week before and the week a month after the campaign starts. The results are in this data link: Day of Week After Before

10/12/22, 7:43 PM Quiz: Practice Exam 2a - Highly Recommended but Optional (42 Questions) https://csufullerton.instructure.com/courses/3331590/quizzes/8290372/take?preview=1 15/19 M 1 6 T 8 3 W 6 8 Th 2 9 F 0 6 S 2 15 Su 7 9 Assume that the number of stops of drunk drivers (before as well as after the campaign) is each normally distributed. Use the following notation: μ(d): The mean of the difference in number of daily stops of drunk drivers between those days after and those days before the campaign. 1 pts Question 33 H(0): μ(d)≥0 Versus H(a): μ(d)<0 H(0): μ(d) < 0 Versus H(a): μ(d)≥0 Specify the null and alternative hypotheses using correct notations. 1 pts Question 34 1.44 1.67 What is the value of the test statistic?

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

10/12/22, 7:43 PM Quiz: Practice Exam 2a - Highly Recommended but Optional (42 Questions) https://csufullerton.instructure.com/courses/3331590/quizzes/8290372/take?preview=1 16/19 -2.05 -1.44 1 pts Question 35 -1.44 1.44 1.94 -1.94 At alpha= 0.05, What is the critical value of the test? 1 pts Question 36 We reject H(0) in favor of H(a) We do not reject H(0) At α=0.05 and using the correct critical value from the preceding question 1 pts Question 37 0.01 0.043076 0.14529072 What is the p-value?

10/12/22, 7:43 PM Quiz: Practice Exam 2a - Highly Recommended but Optional (42 Questions) https://csufullerton.instructure.com/courses/3331590/quizzes/8290372/take?preview=1 17/19 0.05 Use this information to answer the following 6 questions: A study is being conducted to compare the average medical training time for two groups of doctors: those who work for the government and those employed by private hospitals. From a random sample of 22 government-employed doctors, average training time was 62 hours, with a sample standard deviation of 10 hours. In a random sample of 16 doctors working in hospitals, training time was 65.4 hours, with a sample standard deviation of 12.3 hours. Assume that training time for each group is normally distributed. Use the following notations: μ : The mean training time for the population of doctors employed by the government. μ : The mean training time for the population of doctors by private hospitals. The goal of the statistical analysis is to determine whether the sample data support the hypothesis that average training time for government-employed doctors is higher than those employed by private hospitals. 1 2 1 pts Question 38 μ1- μ2 ≥ 0 μ1- μ2 = 0 μ1- μ2 < 0 μ1- μ2 ≤ 0 What is the null hypothesis H(0)?

10/12/22, 7:43 PM Quiz: Practice Exam 2a - Highly Recommended but Optional (42 Questions) https://csufullerton.instructure.com/courses/3331590/quizzes/8290372/take?preview=1 18/19 1 pts Question 39 μ1- μ2 ≥ 0 μ1- μ2 > 0 μ1- μ2 = 0 μ1- μ2 ≤ 0 What is the alternative hypothesis H(a)? 1 pts Question 40 2.83 5.29 10.15 3.74 What is the standard error of x̄ 1- x̄ 2? 1 pts Question 41 0.65 1.22 1.35 -0.9 What is the value of the test statistic?

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Quiz__Practice_Exam_2a_-_Highly_Recommended_but_Optional_42_Questions

Related Documents