Need help please in this homework

taken once. Force Completion This test can be saved and resumed at any point until time has expired. The timer will continue to run if you leave the test. Remaining Time: 2 hours, 54 minutes, 09 seconds. Question Completion Status: Ly Moving to another question will save this response. KMoving to another question will save this response. > Question 4 1 points Save Answer The developer of an energy-efficient lawn mower engine claims that the engine will run continuously for 300 minutes on a single gallon of regular gasoline. Suppose a simple random sample of 50 engines is tested. The engines run for an average of 295 minutes, and the population standard deviation sigma is known to be 20 minutes. Test the null hypothesis that the mean run time is 300 minutes against the alternative hypothesis that the mean run time is not 300 minutes. Use a 0.05 level of significance. State your conclusion: OA There is sufficient evidence that the mean run time for all lawn mower engines is >300 mins. O B. The mean run time for all lawn mower engines is equal to 295 minutes. O C. The correct answer is not among the choices. OD There is insufficient evidence that the mean run time for all lawn mower engines is different from 300 minutes. DE There is sufficient evidence that the mean run time for all lawn mower engines is > Close Window MacBook AirForce Completion This test can be saved and resumed at any point until time has expired. The timer will continue to run if you leave the test. Remaining Time: 2 hours, 53 minutes, 39 seconds. Question Completion Status: Close Window Moving to another question will save this response. 20 Question 24 1 points Save Answer The average growth of a certain variety of pine tree is 10.1 inches in three years. A biologist claims that a new variety will have a greater three year growth. A random sample of 25 of the new variety has an average three-year growth of 10.8 inches and a sample standard deviation of 2.1 inches. The appropriate null and alternate hypotheses to test the biologist's claim are: "Ho: p = 10.1 against Ha: H > 10.8 O B. "Ho: p = 10.8 against Ha: H > 10.8 Ho: p = 10.1 against Ha: H > 10.1 OD. Ho: J = 10.8 against Ha: p # 10.8 OE "The correct answer is not among the choices. Moving to another question will save this response. Close Window MacBook AirRemaining Time: 2 hours, 54 minutes, 54 seconds. Question Completion Status: .> Moving to another question will save this response. Question 16 Grades on a Chemistry test follow a normal distribution with a mean of 65 and a standard deviation of 12. What is the approximate 90th percentile of the grade distribution? O A. 95 O B. 75 O C. 85 OD. 80 OE. 90 A Moving to another question will save this response. MacBook AirXO A Remaining Time: 2 hours, 55 minutes, 49 seconds. * Question Completion Status: Close Window Moving to another question will save this response. > Question 12 1 points Save Answer A certain railway company claims that its trains run late 5 minutes on the average. The actual times (minutes) that 10 randomly selected trains ran late were provided giving a sample mean = 9.130 and sample standard deviation s = 1.4 . In testing the company's claim, (2-sided test) at the significance level of 0.01 and assuming normality the value of the test statistic and the critical values are, respectively: OA The correct answer is not among the choices. O B. 8.79 and +2.764 OC 8.79 and +2.576 OD. 5.91 and +2.2622 OE 9.33 and 13.25 > 1) Moving to another question will save this response. Close Window MacBook AirWarnings appear when ha the time, 5 minutes, 1 minute, and 30 seconds remain, Multiple Attempts Not allowed. This test can only be taken once. Force Completion This test can be saved and resumed at any point until time has expired. The timer will continue to run if you leave the test. Remaining Time: 2 hours, 57 minutes, 57 seconds. Question Completion Status: Close Window L Moving to another question will save this response. > Question 3 1 points Save Answer The developer of an energy-efficient lawn mower engine claims that the engine will run continuously for 300 minutes on a single gallon of regular gasoline. Suppose a simple random sample of 50 engines s tested. The engines run for an average of 295 minutes, and the population standard deviation sigma is known to be 20 minutes. Test the null hypothesis that the mean run time is 300 minutes against the alternative hypothesis that the mean run time is not 300 minutes. Use a 0.05 level of significance. State the critical value(s) for this test. O AZ = $1.96 O B. Z = +1.645 O C.t = +2.093 OD. Z = +2.326 OE The correct answer is not among the choices. Moving to another question will save this response. .005 OE .025

Moving to another question will save this response MacBook Air 44 FB F9 F10 esc -6: 20 F7 F3 F4 F5 F6 FI F2 # $ % & @ 8 9 3 5 2 4 63 Blackboard Remaining Time: 2 hours, 56 minutes, 54 seconds. Question Completion Status: Close Window Ly Moving to another question will save this response. > Question 8 1 points Save Answer Winnipeg Tribune claims that the time of travel from downtown to the University via the Pembina bus has an average of u = 27 minutes. A student who normally takes this bus believes that u is less than 27 minutes. A sample of six ride-times taken to test the hypothesis of interest gave mean = 26.5 minutes and standard deviation, s = 2.43 minutes. The value of the test statistic for testing this hypothesis is: OA - 0.532 O B. 0.504 OC. 0.460 OD. - 0.504 OE - 0.460 A Moving to another question will save this response. Close Window MacBook Air3 Blackboard x Z A Remaining Time: 2 hours, 57 minutes, 21 seconds. * Question Completion Status: Close Window 4 Moving to another question will save this response. > Question 6 I points Save Answer It is known from past years that the average IQ of Commack elementary students is at least 110. The principal thinks that this is an overestimate, and that the average IQ of students here is less than 110. The principal administers an IQ test to 20 randomly selected students. Among the sampled students, the average IQ is 104 with a standard deviation of 10. Assume a significance level of 0.05 and conduct a hypothesis test Calculate the test statistic. OA Z=-2.539 O B. 1=-2.68 O C. Z = 2.576 DD. "The correct answer is not among the choices. OE t = 2.68 Moving to another question will save this response. Moving to another question will save this response. Question 14 1 points Save Answer A certain railway company claims that its trains run late 5 minutes on the average. The actual times (minutes) that 10 randomly selected trains ran late were provided giving a sample mean = 9.130 and sample standard deviation s = 1.4 . In testing the company's claim, (2-sided test) at the significance level of 0.01 and assuming normality Find a 99% confidence interval and state which of the following is true about trains belonging to this railway company? OA. We do not have enough evidence to reject the claim that the trains run late an average of 5 minutes since the value of 5 is included in the 99% confidence interval. DB. We would reject the claim that the trains run late an average of 5 minutes and conclude that they run late an average of more than 5 minutes since the 99% confidence interval exceeds 5. O C. We would reject the claim that the trains run late an average of 5 minutes and conclude that they run late an average of less than 5 minutes since 5 exceeds the entire 99% confidence interval. OD. "We conclude that the trains run late an average of 9.13 minutes. OE_ The correct answer is not among the choices. > Question 10 1 points Save Answer One of the side effects of flooding a lake in northern boreal forest areas (e.g. for a hydro-electric project) is that mercury is leached from the soil, enters the food chain, and eventually contaminates the fish. The concentration in fish will vary among individual fish because of differences in eating patterns, movements around the lake, etc. Suppose that concentrations of mercury in individual fish follow an approximate normal distribution with a mean of 0.25 ppm and a standard deviation of 0.08 ppm. Fish are safe to eat if the mercury level is below 0.30 ppm. What proportion of fish are safe to eat? DB. 23% 69% OD 63% OE 27% Moving to another question will save this response. Question 11 1 points Save Answer T-Table.pdf standardnormaltable.pdf One of the side effects of flooding a lake in northern boreal forest areas (e.g. for a hydro-electric project) is that mercury is leached from the soil, enters the food chain, and eventually contaminates the fish. The concentration in fish will vary among individual fish because of differences in eating patterns, movements around the lake, etc. Suppose that concentrations of mercury in individual fish follow an approximate normal distribution with a mean of 0.25 ppm and a standard deviation of 0.08 ppm. Fish are safe to eat if the mercury level s below 0.30 ppm. The Department of Fisheries and Oceans wishes to know the mercury level of the bottom 20% of the fish. The appropriate percentile and mercury level for this lake is: 20th percentile has a value of 0.18 ppm DB. 20th percentile has a value of -0.84 ppm D C. 80th percentile has a value of 0.32 ppm DD. The correct answer is not among the choices. DE 80th percentile has a value of 0.84 ppm Moving to another question will save this response. Close Window MacBook AirRemaining Time: 2 hours, 54 minutes, 02 seconds. * Question Completion Status: L> Moving to another question will save this response. Question 22 The probability of contracting a stomach virus while visiting Mexico is 60%. Find the probability that amongst 15 students visiting Mexico, Exactly five students contract a stomach virus: OA. .7065 O B. The correct answer is not among the choices. O C. .0755 OD. .0245 OE .2938 Ly A Moving to another question will save this response. MacBook AirSimply scroll up to a question which has tables as an attachment to necess the tables if you need them. Use the calculator whenever you can. Instructions Timed Test This test has a time limit of 3 hours. This test will save and submit automatically when the time expires. Warnings appear when half the time, 5 minutes, 1 minute, and 30 seconds remain. Multiple Attempts Not allowed. This test can only be taken once. Force Completion This test can be saved and resumed at any point until time has expired. The timer will continue to run If you leave the test. Remaining Time: 2 hours, 57 minutes, 05 seconds. * Question Completion Status: Close Window Moving to another question will save this response. 30 Question 7 1 points Save Answer It is known from past years that the average IQ of Commack elementary students is at least 110. The principal thinks that this is an overestimate, and that the average IQ of students here is less than 110. The principal administers an IQ test to 20 randomly selected students. Among the sampled students, the average IQ is 104 with a standard deviation of 10. Assume a significance level of 0.05 and conduct a hypothesis test. Estimate the p-value for this test. A .005

>> > Moving to another question will save this response. MacBook Air F9 F10Instructions Timed Test This test has a time limit of 3 hours. This test will save and submit automatically when the time expires. Warnings appear when half the time, 5 minutes, 1 minute, and 30 seconds remain. Multiple Attempts Not allowed. This test can only be taken once. Force Completion This test can be saved and resumed at any point until time has expired. The timer will continue to run if you leave the test. Remaining Time: 2 hours, 56 minutes, 40 seconds. Question Completion Status: Close Window Moving to another question will save this response. Question 9 points Save Answ Winnipeg Tribune claims that the time of travel from downtown to the University via the Pembina bus has an average of p = 27 minutes. A student who normally takes this bus believes that u is less than 27 minutes. A sample of six ride-times taken to test the hypothesis of interest gave mean - 26.5 minutes and standard deviation, s = 2.43 minutes. In the previous question, describe the critical region and state the conclusion when testing at alpha = .05 ; OA_ The correct answer is not among the choices. O B. reject Ho if to 2.571; our conclusion is reject Ho. OD reject Ho if to 2.015; our conclusion is fail to reject Ho. Moving to another question will save this response > Question 5 1 points Save Answer It is known from past years that the average IQ of Commack elementary students is at least 110. The principal thinks that this is an overestimate, and that the average IQ of students here is less than 110. The principal administers an IQ test to 20 randomly selected students. Among the sampled students, the average IQ is 104 with a standard deviation of 10. Assume a significance level of 0.05 and conduct a hypothesis test. State the critical value(s) for this test OA 1=-1.729 O B 1= +2.539 O c. 1 = 12.326 O D. "The correct answer is not among the choices. OE 1=-2.539 > LA Moving to another question will save this response. Close Window MacBook Airinstructions Timed Test This test has a time limit of 3 hours. This test will save and submit automatically when the time expires. Warnings appear when half the time, 5 minutes, 1 minute, and 30 seconds romain. Multiple Attempts Not allowed. This test can only be taken once. Force Completion This test can be saved and resumed at any point until time has expired. The Jones will continue to run If you leave the test. Remaining Time: 2 hours, 58 minutes, 22 seconds. Question Completion Status: Close Window Moving to another question will save this response. > Question 2 1 points Save Answer The developer of an energy-efficient lawn mower engine claims that the engine will run continuously for 300 minutes on a single gallon of regular gasoline. Suppose a simple random sample of 50 engines is tested. The engines run for an average of 295 minutes, and the population standard deviation sigma is known to be 20 minutes. Test the null hypothesis that the mean run time is 300 minutes against the alternative hypothesis that the mean run time is not 300 minutes. Use a 0.05 level of significance. Estimate the p-value for this test. O A. .9232 O B. .9616 O C. .0384 OD. .0248 OE .0768 Moving to another question will save this response. MacBook AirRemaining Time: 2 hours, 54 minutes, 45 seconds. * Question Completion Status: .> Moving to another question will save this response. Question 17 In a survey, three out of four students said that courts show too much concern for criminals. Find the probability that of seventy randomly selected students Exactly sixty-eight feel that courts show too much concern. OA .8265 O B. .3248 O C. .2496 OD. 0 OE > Moving to another question will save this response. MacBook AirRemaining Time: 2 hours, 54 minutes, 30 seconds. Question Completion Status: Moving to another question will save this response. Question 19 In a survey, three out of four students said that courts show too much concern for criminals. Find the probability that of seventy randomly selected students At least 56 feel that courts show too much concern O A. OB. .21 OC. OD. .25 OE Moving to another question will save this response. MacBook Air