Exam 16 November 2020, questions and answers PDF

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Statistics and Probability (STAT-112)Grade 11 Week 11-AMALEAKS.BLOGSPOTThe “p hat” is calculated as Select one: a. Number of desired elements over the number of desired outcomes b. Number of desired outcomes over the number of desired elements Correct c. 1- (Number of desired elements over the numbe...

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Statistics and Probability (STAT-112) Grade 11 Week 11-20 AMALEAKS.BLOGSPOT.COM The “p hat” is calculated as Select one: a. Number of desired elements over the number of desired outcomes b. Number of desired outcomes over the number of desired elements Correct c. 1- (Number of desired elements over the number of desired outcomes) d. (Number of desired outcomes over the number of desired elements) – 1 Feedback The correct answer is: Number of desired outcomes over the number of desired elements Sampling distribution of proportions is ______________ distributed Select one: a. Normally Correct b. Randomly c. Evenly d. Unevenly Feedback The correct answer is: Normally A survey was conducted to 300 Grade 10 students who have Internet access to determine who access social media websites after attending classes. Based on the survey, 250 students responded Yes. What is the population proportion to students who do not access social media after attending classes? Select one: a. 80% b. 20%

c. 17% Correct d. 83% Feedback The correct answer is: 17% When the confidence level is 95%, the ____________________ are +- 1.96 Select one: a. Margin of Errors b. Confidence coefficients Correct c. Confidence intervals d. “p hat” values Feedback The correct answer is: Confidence coefficients Point estimate is Select one: a. Always equal to the number or samples b. A range of possible values for a population parameter. c. Equal to the population mean d. A statistical that estimates a population parameter Correct Feedback The correct answer is: A statistical that estimates a population parameter The Dp is the ____________ estimate of p.

Select one: a. balanced b. unbiased Correct c. biased d. inverse Given n=10, x¯ =28, s=2.0, 95% confidence. Assuming that the samples come from a normal distribution, find the margin of error.

Select one: a. 1.24 Correct b. 26.76 c. 3.16 d. 0.63 Feedback The correct answer is: 1.24 Given n=10, x¯ =28, s=2.0, 99% confidence. Assuming that the samples come from a normal distribution, find the interval estimate of the population mean. Select one: a. (11.34, 14.89) b. (1.63, 2.25) c. (21.36, 24.63) d. (26.36, 29.63) Correct Feedback The correct answer is: (26.36, 29.63) What is in the center of the confidence interval? Select one: a. Margin of Error b. Point Estimate Correct c. Population Parameter d. Number of samples Feedback The correct answer is: Point Estimate In a survey of 500 individuals, 300 likes to eat dinner in a restaurant. Estimate the sample proportion ^p of those who like to eat dinner in a restaurant based on the sample. Select one: a. 45%

b. 0.40 c. 55% d. 0.60 Correct Feedback The correct answer is: 0.60 As the confidence interval for a given statistics increases in length, the confidence level ___________.

A: Increases - correct Learning Activity 8 Stats Margin of error is Select one: a. the product of confidence coefficient and standard deviation divided by the square root of the sample size Correct b. the quotient of confidence coefficient and standard deviation multiplied by the square root of the sample size c. the product of confidence coefficient and square root of the sample size divided by standard deviation d. the quotient of confidence coefficient and square root of the sample size divided standard deviation Feedback The correct answer is: the product of confidence coefficient and standard deviation divided by the square root of the sample size Given n=100, x¯ =45, s=2.0, 90% confidence. Assuming that the samples come from a normal distribution, find the interval estimate of the population mean. Select one: a. (42.103, 43.970) b. (43.355, 46.645) c. (44.461, 45.329) Incorrect d. (46.921, 47.727) Feedback The correct answer is: (43.355, 46.645) Given n=100, x¯ =80, s=2.0, 95% confidence. Assuming that the samples come from a normal distribution, find the margin of error.

Select one: a. 0.348 Incorrect b. 0.20 c. 0.392 d. 0.196 Feedback The correct answer is: 0.392 A survey was conducted from the 250 individuals. Based on the result of the survey, 170 are satisfied with the current Local Government administration. Estimate the sample proportion ^p of those who are not satisfied based on the sample provided. Select one: a. 55% b. 0.32 Correct c. 0. d. 0.68 Feedback The correct answer is: 0.32 A survey was conducted to 110 college students to determine who are using the Library Resource Center of the university. Based on the survey, only 30% responded Yes. Based on the survey, how many students are not using the Library Resource Center? Select one: a. 33 b. 30 c. 67 Correct d. 70 Feedback The correct answer is: 67

Learning Activity 9 Stats A survey of 200 people finds that they work on average of 8 hours a day. If the margin of error at 98% confidence level is 1.2 hours. How do you compute for the lower confidence interval? Select one: a. 8 hours less 1.2 hours b. Z score plus less the square root of 8 hours less 1.2 hours Correct c. None of the choices d. 8 hours less 1.2 hours multiplied by the z score at 98% confidence level Feedback The correct answer is: Z score plus less the square root of 8 hours less 1.2 hours King Lo Electronics claims that the new brand of computer will last for 25,000 hours. A research company conducted a test on the information. The company randomly select and test 100 cellular phone. The data from the sample shows that the mean life of the cellular phone is 20,000 hours, with a standard deviation of 1000 hours. Determine the 95% confidence interval of the mean life of the cellular phone. Select one: a. (17,482, 18,649) b. (19,804, 20,196) Correct c. (23,467, 24,639) d. (26,928, 27,375) Feedback The correct answer is: (19,804, 20,196) Given the sample size (n=400) and sample proportion (p=0.56), find the approximate margin of error for the 99% confidence interval: Select one: a. 0.043 Incorrect b. 0.052 c. 0.064 d. 0.074 Feedback

The correct answer is: 0.064 Given the sample size (n=200) and sample proportion (p=0.70), find the approximate margin of error for the 90% confidence interval: Select one: a. 0.053 b. 0.085 c. 0.072 Incorrect d. 0.039 Feedback The correct answer is: 0.053 A private organization telephone poll of 750 adults, aged 18 and older, living in the country found that 60% of citizen feel confident in the accuracy of their doctor's advice, and don't feel the need to check for a second opinion or do additional research. The margin of error for this survey was given as ± 20 percentage points. Find a 95% confidence interval estimate of the percent of adults who feel confident in the accuracy of their doctor’s advice and don’t feel the need to check for a second opinion. Select one: a. (0.490, 0.601) b. (0.452, 0.538) c. (0.565, 0.640) Correct d. (0.316, 0.483) Feedback The correct answer is: (0.565, 0.640)

Short Quiz 9 Given the sample size (n=400) and sample proportion (p=0.70), find the approximate margin of error for the 99% confidence interval: Select one: a. 0.086

b. 0.059 c. 0.039 Incorrect d. 0.330 Feedback The correct answer is: 0.059 Suppose a new cancer treatment is given to a sample of 500 patients. The treatment was successful for 300 of the patients. Assume that these patients are representative of the population of individuals who have this cancer. Determine a 90% confidence interval for the proportion successful treated. Select one: a. 0.564 < p < 0.640 b. 0.640 < p < 0.742 Incorrect c. 0.742 < p < 0.834 d. 0.834 < p < 0.927 Feedback The correct answer is: 0.564 < p < 0.640 A private organization telephone poll of 900 adults, aged 18 and older, living in the country found that 75% of citizen feel confident in the accuracy of their doctor's advice, and don't feel the need to check for a second opinion or do additional research. The margin of error for this survey was given as ±10 percentage points. Find a 90% upper confidence interval estimate of the percent of adults who feel confident in the accuracy of their doctor’s advice and don’t feel the need to check for a second opinion. Select one: a. 0.077 b. 0.329 Incorrect c. 0.834 d. 0.290 Feedback The correct answer is: 0.077 Lim Electronics claims that the new brand of cellular phone will last for 80,000 hours. A research company conducted a test on the information. The company randomly select and test 100 cellular

phone. The data from the sample shows that the mean life of the cellular phone is 60,000 hours, with a standard deviation of 1500 hours. Determine the 95% confidence interval of the mean life of the cellular phone. Select one: a. (79,301 , 80,890) Incorrect b. (59,706 , 60,294) c. (59,301 , 60,890) d. (79,706 , 80,294) Feedback The correct answer is: (59,706 , 60,294) A survey of 900 female finds that they sleep on average of 8 hours a day. If the margin of error at 95% confidence level is 1.3 hours. Find the confidence interval? Select one: a. 4.50 hours < p < 5.89 hours b. 6.70 hours < p < 9.30 hours Correct c. 8.66 hours < p < 11.26 hours d. 7.34 hours < p < 8.66 hours Feedback The correct answer is: 6.70 hours < p < 9.30 hours Given the sample size (n=300) and sample proportion (p=0.56), find the approximate margin of error for the 90% confidence interval: Select one: a. 0.055 b. 0.069 c. 0.047 Correct d. 0.039 Feedback The correct answer is: 0.047 Given the problem in item 9, what does the answer tells about?

Select one: a. Lim Electronics can use the survey conducted for their advertisements. b. The confidence interval does not support the claim of Lim Electronics. c. The confidence interval support the claim of Lim Electronics. Incorrect d. The information is not sufficient to conclude. Feedback The correct answer is: The confidence interval does not support the claim of Lim Electronics. A survey of 900 people finds that they work on average of 9 hours a day. If the margin of error at 98% confidence level is 1.5 hours. What is the solution to find the lower confidence interval? Select one: a. Z score plus less the square root of 9 hours less 1.5 hours b. None of the choices c. 9 hours less 1.5 hours Correct d. All of the choices e. 9 hours less 1.5 hours multiplied by the z score at 98% confidence level A private organization telephone poll of 900 adults, aged 18 and older, living in the country found that 75% of citizen feel confident in the accuracy of their doctor's advice, and don't feel the need to check for a second opinion or do additional research. The margin of error for this survey was given as ±10 percentage points. Find a 90% lower confidence interval estimate of the percent of adults who feel confident in the accuracy of their doctor’s advice and don’t feel the need to check for a second opinion. Select one: a. 0.0726 b. 0.8932 c. 0.4508 Incorrect d. 0.0934 Feedback The correct answer is: 0.0726 Suppose a new cancer treatment is given to a sample of 500 patients. The treatment was successful for 300 of the patients. Assume that these patients are representative of the population of individuals who have this cancer.

Calculate the sample proportion that was successfully treated. Select one: a. 0.85 Incorrect b. 0.72 c. 0.30 d. 0.60 Feedback The correct answer is: 0.60

Learning Activity 10 Stats Find the sample size given 95% confidence, Margin of Error = 0.15 and p ^ =0.25. Select one: a. 34 Incorrect b. 33 c. 31 d. 32 Feedback The correct answer is: 33 Find the sample size given 90% confidence, Margin of Error = 0.15 and ^p =0.25. Select one: a. 20 Incorrect b. 22 c. 23 d. 21 Feedback The correct answer is: 23 Find the sample size given 99% confidence, Margin of Error = 0.10 and ^p =0.35. Select one:

a. 389 b. 215 Incorrect c. 139 d. 152 Feedback The correct answer is: 152 Find the sample size given 99% confidence, Margin of Error = 0.18 and ^p =0.30. Select one: a. 41 b. 42 c. 44 Incorrect d. 43 Feedback The correct answer is: 43 The Engineer of the building wants to use the proportion of the population to determine the sample size needed to interview regarding their idea about the new color design of the building. He wants to be able to assure with probability 0.90 that his error will be most 0.10. Similar surveys during past year that 85% approved the new color design. How large a sample does the Engineer need? Select one: a. 278 Incorrect b. 2,145 c. 1,372 d. 196 Feedback The correct answer is: 196

Short Quiz 11 Stats Determine whether each of the following is a null of an alternative hypothesis:

The proportion of computer in the software laboratory is lower than the total number of BS IT students in the university. Answer: alternative hypothesis Correct Feedback The correct answer is: Alternative hypothesis The alternative hypothesis and null hypothesis should be ________________. Select one: a. Mutually exclusive b. All of the choices c. None of the choices d. Mutually inclusive Correct Feedback The correct answer is: Mutually inclusive Determine whether each of the following is a null of an alternative hypothesis: The proportion of an employee income is greater than the monthly expenses of the employee. Answer: null hypothesis Incorrect Feedback The correct answer is: Alternative hypothesis William collected a random sample of 88 people, asking how many times they open ABC web site per day on average, and calculated x¯ = 50.30. ABC suggests that µ = 55, and s = 10. William thinks the actual mean is less than the website owner claims. What is the null and alternative hypothesis? Select one: a. 55 b. Null hypothesis µ = 55, Alternative hypothesis µ < 55 c. Null hypothesis µ ? 55, Alternative hypothesis µ

d. Null hypothesis µ > 55, Alternative hypothesis µ = 55 e. 55, Alternative hypothesis µ ? 55 Correct f. Null hypothesis µ Feedback The correct answer is: Null hypothesis µ ≥ 55, Alternative hypothesis µ < 55 A type of test that is denoted by the symbol Ho. Select one: a. Rejection hypothesis Incorrect b. Statistical hypothesis c. Alternative hypothesis d. Null hypothesis Feedback The correct answer is: Null hypothesis The probability of making type I error is Select one: a. ß b. 1- a c. 1- ß d. a Correct e. µ - a Feedback The correct answer is: a For the 99% confidence level, Select one: a. a b. a c. a d. 0.001

e. a f. 0.010 g. 0.005 h. 0.025 Correct Feedback The correct answer is: 0.010 Determine whether each of the following is a null of an alternative hypothesis: A police precinct claims that there is ten crimes on the average are reported. Answer: alternative hypothesis Incorrect Feedback The correct answer is: Null hypothesis This refers to the area where the value of the test statistic lies for which we will reject the null hypothesis. Select one: a. Rejection region and Null region b. Rejection region and Critical region Correct c. Null region and Critical region d. Null region e. Critical region f. None of the choices g. Rejection region h. All of the choices Feedback The correct answer is: Rejection region and Critical region

Learning Activity 11 Stats Determine whether each of the following is a null of an alternative hypothesis: The average income of an employee is 12,000 pesos. Answer: null hypothesis Correct Feedback The correct answer is: Null hypothesis The level of significance is the Select one: a. 1 - p value b. Same as confidence interval c. Maximum allowable probability of Type II error d. Minimum allowable probability of Type II error e. Probability of committing a Type I error Correct Feedback The correct answer is: Probability of committing a Type I error What is the null hypothesis to the claim that people like android phone than IOS? State the null hypothesis. Select one: a. Less people like IOS than android b. More people like android than IOS phone Correct c. Less people like android and IOS phone d. More people like IOS phone than android phone Feedback The correct answer is: More people like android than IOS phone

If the null hypothesis is true and rejected, the decision is incorrect – Type I Error Select one: a. Rejection Error b. Type I Error Correct c. Correction Error d. Type II Error Feedback The correct answer is: Type I Error Determine whether each of the following is a null of an alternative hypothesis: The average internet usage of a College student is 6 hours. Answer: null hypothesis Correct Feedback The correct answer is: Null hypothesis

Learning Activity 12 Stats In hypothesis testing, the computed statistics is compared to the critical value for decision making. Select one: a. The statement is TRUE. Correct b. The statement is FALSE. Feedback The correct answer is: The statement is TRUE. This separates the rejection region to the region where we do not reject the null hypothesis. Select one: a. Z score b. Null value Incorrect c. Critical value

d. chi value The correct answer is: Critical value Given a=0.05 and the test statistics, decide whether the null hypothesis is to be rejected or accepted: –4 Select one: a. Do not Reject b. Reject Correct c. Cannot be determined Feedback The correct answer is: Reject St. Therese senior high school have an average achievement test score of 96. From a random sample of 49 students St. Therese students we find the average achievement test score to be 98 with a standard deviation of 88. We want to know if these high school students are representative of the overall population. What can we conclude based? Select one: a. Accept null hypothesis b. Reject null hypothesis c. Accept alternative hypothesis Incorrect d. Reject alternative hypothesis Feedback The correct answer is: Accept null hypothesis Given a=0.05 and the test statistics, decide whether the null hypothesis is to be rejected or accepted: 2.35 Select one: a. Cannot be determined b. Reject c. Do not Reject Incorrect Feedback The correct answer is: Reject

Suppose that the z is the test statistics for hypothesis testing, calculate the value of the z for each of the following. Express your answer in 2 decimal places. µ = 25, s = 5, n = 80, x¯ = 23.4 Answer: -5 - wrong Incorrect Feedback The correct answer is: -2.86 Suppose that the z is the test statistics for hypothesis testing, calculate the value of the z for each of the following. Express your answer in 2 decimal places. µ = 77, s = 6, n = 109, x¯ = 78.2 Answer: -12.83 Incorrect Feedback The correct answer is: 2.09 Suppose that the z is the test statistics for hypothesis testing, calculate the value of the z for each of the following. Express your answer in 2 decimal places. µ = 8, σ = 4, n = 99, x] = 7.2 A: -1.99 - correct

Short Quiz 12 Consider the scenario: In a recent survey, 320 persons out of 35 reported that they prefer to ride in a public utility air-conditioned vehicle rather than a jeepney. What is the value of the test statistics? Select one: a. 3.49 Incorrect b. – 1.85 c. – 1.85 d. – 1.33 Feedback The correct answer is: – 1.85 Supposed that the z is the test statistics for hypothesis testing, calculate the value of the z for each of the following. Express your answer in 2 decimal places.

µ = 8.5, s = 4, n = 99, x¯ = 7.2 Answer: 34.32 - wrong Incorrect Feedback The correct answer is: -3.23 Given a=0.05 and the test statistics, decide whether the null hypothesis is to be rejected or accepted: 3.31 Select one: a. Cannot be determined b. Reject Correct c. Do not Reject Consider the scenario: In a recent survey, 320 persons out of 35 reported that they prefer to ride in a public utility air-conditioned vehicle rather than a jeepney. What can we conclude based the value of the test statistics? Select one: a. Reject null hypothesis b. Accept alternative hypothesis Incorrect c. Reject alternative hypothesis d. Accept null hypothesis Feedback The correct answer is: Accept null hypothesis Values supporting the ___________________ occurs in the rejection region. Select one: a. Critical values b. Alternative hypothesis and critical values Incorrect c. Null hypothesis d. Null hypothesis and critical values

e. Alternative hypothesis Feedback The correct answer is: Null hypothesis and critical values A sample is small when n=30. Select one: a. The statement is TRUE. Incorrect b. The statement is FALSE. Replace the letter n with letter x. c. The statement is FALSE. Replac...