1) Problem #PRAJ9EP "PRAJ9EP - 267294 - Using the compute..." |
A)
Using the computer output below, fill in the value for A. Round answer to the nearest hundredth. © STATS4STEM.ORG |
B)
Calculate the value of B. Round answer to the nearest hundredth. |
C)
Calculate the p-value for the following null and alternative hypothesis test: |
D)
Calculate the lower limit of a 95% confidence interval for β, the true slope of the least squares regression line. Round only at the END of the problem. Round final answer to the closest hundredth. |
E)
Fill in the following blank to make the statement below a proper interpretation of the calculated confidence interval. Based on my analysis, I can be 95% ____________________ that β, the true slope of the least squares regression line, falls between -0.14 and 0.27. |
2) Problem #PRAJB76 "PRAJB76 - 240184 - A coffee mug manu..." |
A)
A coffee mug manufacturer calculated a 90% confidence interval for the average weight of a box of mugs to be: (21.3 lbs, 23.6 lbs). From this information, we can conclude: CHECK ALL THAT APPLY © STATS4STEM.ORG |
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B)
A coffee mug manufacturer calculated a 95% confidence interval for the amount of coffee held in their new Jumbo coffee mugs to be: (19.3 oz, 21.4 oz). From this information, we can conclude: CHECK ALL THAT APPLY If the manufacturer were to repeat the process of constructing a confidence interval, but was to significantly increase the sample size, the new margin of error would be smaller than that calculated the first time. |
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C)
If one wanted to reduce the margin of error for a 90% confidence interval by half by holding all things constant except for the sample size, one would need to: |
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3) Problem #PRAKMJR "PRAKMJR - Copier vs copier analysis" |
A)
A purchasing manager for a local school district was approached by a salesman for ACME copying machines. The salesman claimed "If we install a new machine, it will be the most reliable copier you've ever used!". The purchasing manager was intrigued as there was nothing more annoying than paper jams. However, he had fallen victim to past claims that had turned out to be untrue. He asked the salesman to prove his claim. The manager informed him that his current machine, a JAMFREE, is the most reliable copier that he has ever used and that the new machine must prove it's superiority. They decide to run an experiment. The experiment consisted of running 300 equally demanding batches through both machines. Some of the batches demanded staples, some double sided, but both machines were subject to the same tests. A week went by and the results came back. The new ACME machine produced 43 batches where at least 1 paper jam was reported out of a total of 300 batches run, while the JAMFREE produced 54 batches where at least 1 paper jam was reported out of a total of 300 batches run. What is the best formula to calculate the test statistic for this problem? A. B. C. D. E. F. © STATS4STEM.ORG |
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B)
Which of the following represent the correct null and alternative hypothesis? Notation: A - ACME; J - JAMFREE
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C)
What assumptions and condition must be checked before proceeding with your test of significance? |
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D)
Calculate p-hat (not p-hat1 or p-hat2) for the formula shown below as it pertains to this problem. Round answer to the nearest hundredth. |
E)
Based on the alternative hypothesis stated above, which of the following statements is correct? A) p-hat1 should be 54/300 and p-hat2 should be 43/300 so that the numerator of the fraction will be positive, and the z value will be positive too. This is ideal as the alternative hypothesis rejects on the right tail. B) p-hat1 should be 43/300 and p-hat2 should be 54/300 so that the numerator of the fraction will be negative, and the z value will be negative too. This is ideal as the alternative hypothesis rejects on the left tail. C) p-hat1 should be 54/300 and p-hat2 should be 43/300 so that the numerator of the fraction will be positive, and the z value will be positive too. This is ideal as the alternative hypothesis rejects on the left tail. D) p-hat1 should be 43/300 and p-hat2 should be 54/300 so that the numerator of the fraction will be negative, and the z value will be negative too. This is ideal as the alternative hypothesis rejects on the right tail. |
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G)
Which of the formulas found on the AP formula sheet can be used to help one remember/create the test statistic formula needed for a hypothesis test for a problem pertaining to the difference of proportions? |
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H)
Using a significance level is 0.05, the best conclusion would be: A) I calculated a p-value of 0.11, which is greater than the stated significance level of 0.05. Therefore, we can reject the null hypothesis. B) Reject the null hypothesis. C) I calculated a p-value of 0.11, which is greater than the stated significance level of 0.05. Therefore, we fail to reject the null hypothesis. The data proves that the proportion of batches creating at least 1 paper jam is equal for ACME and JAMFREE copying machines. D) I calculated a p-value of 0.11, which is greater than the stated significance level of 0.05. Therefore, we reject the null hypothesis. The data supports the claim tthat the proportion of batches creating at least 1 paper jam is less for the ACME copying machine than the JAMFREE copying machine. E) I calculated a p-value of 0.11, which is greater than the stated significance level of 0.05. Therefore, we fail to reject the null hypothesis. F) I calculated a p-value of 0.11, which is greater than the stated significance level of 0.05. Therefore, we fail to reject the null hypothesis. The data fails to support the claim that the proportion of batches creating at least 1 paper jam is less for the ACME copying machine than the JAMFREE copying machine. G) Fail to reject the null hypothesis. |
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4) Problem #PRAFHH2 "PRAFHH2 - t-star for CI" |
What is t* for a 90% Confidence Interval where the sample size is 39? Give answer exactly as found in the t-table. Click here for a t-table. © STATS4STEM.ORG |
5) Problem #PRAKPMQ "PRAKPMQ - 279974 - Ricki goes to the..." |
A)
Ricki goes to the toy store with 3 dollars. He wants to buy a bag of marbles. He randomly chooses 15 beautiful marbles. The marbles cost 1 penny per gram. If the weight of each marble is normally distributed with a mean of 19.5 grams and a standard deviation of 1.5 grams, what is the mean weight for the weight of bags containing 15 marbles? Assume that the weight of the bags holding the marbles is negligible. Round answer to the nearest hundredth. © STATS4STEM.ORG |
B)
What is the standard deviation for the weight of bags containing 15 marbles? Assume that the weight of the bag holding the marbles to be negligable. Round answer to the nearest hundredth. |
C)
Ricki brings his bag of 15 marbles to the checkout counter to be weighed. What is the probability that he doesn't have enough money to buy the marbles? Round answer to the nearest hundredth. Link to z-table. |
6) Problem #PRAKPMS "PRAKPMS - 279976 - Definition:  ..." |
Definition: Every individual in a population is assigned to one, and only one group. Then a sample of groups is chosen using a simple random sample and then individuals are sampled from the chosen groups. Which sampling method is described by this definition? © STATS4STEM.ORG |
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7) Problem #PRAJBQG "PRAJBQG - 239698 - Undercoverage is ..." |
Undercoverage is when ___________________. a. an individual chosen for the sample can't be contacted or does not cooperate b. some groups in the population are left out of the process of choosing the sample c. there are too little people in the sample d. there are too little people in the population © STATS4STEM.ORG |
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8) Problem #PRAKPMT "PRAKPMT - Paper Jam Test" |
A)
A purchasing manager for a local school district was approached by a salesman for ACME copying machines. The salesman claimed "If we install a new machine, it will be the most reliable copier you've ever used!". The purchasing manager was intrigued as there was nothing more annoying than paper jams. However, he had fallen victim to past claims that had turned out to be untrue. He asked the salesman to prove his claim. The manager informed him that his current machine, a JAMFREE, is the most reliable copier that he has ever used and that the new machine must prove it's superiority. They decide to run an experiment. The experiment consisted of running 300 equally demanding batches through both machines. Some of the batches demanded staples, some double sided, but both machines were subject to the same tests. A week went by and the results came back. The new ACME machine produced 43 batches where at least 1 paper jam was reported out of a total of 300 batches run, while the JAMFREE produced 54 batches where at least 1 paper jam was reported out of a total of 300 batches run. What is the best formula to calculate a confidence interval for the difference of proportions? A.
B. C. D. E. F. © STATS4STEM.ORG |
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B)
What assumptions and condition must be checked before calculating a confidence interval for the difference of proportions? |
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C)
Calculate a 90% confidence interval for the difference in the proportion of batches run with at least 1 jam for the ACME copying machine and the proportion of batches run with at least 1 jam for the JAMFREE copying machine. Link to t-table. |
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D)
Which of the formulas found on the AP formula sheet can be used to help one remember/create the formula for the confidence interval for a problem pertaining to the difference of proportions? |
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E)
Based on the confidence interval calculated previously, explain why the calculated confidence interval fails to support the claim that the proportion of batches creating at least 1 paper jam is less for the ACME copying machine than the JAMFREE copying machine. |
9) Problem #PRAKPMV "PRAKPMV - 279979 - The correct inter..." |
The correct interpretation for the p-value is: *** MEMORIZE DEFINITION FOR THE AP EXAM *** © STATS4STEM.ORG |
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10) Problem #PRAKPMW "PRAKPMW - 279980 - Review: A&n..." |
A)
Review: A factor is a major independent variable. While a level is a subdivision of a factor. Combinations of factor levels are called treatments. Question: An educational researcher wishes to vary the amount of review ASSISTments that students receive for instructional purposes. One group will be getting 1 review ASSISTment per week and another group would get 2 review ASSISTments per week. And the researcher will vary the setting of the review assignments by having one group getting the review assignment in-class while the other group would get the review assignment for homework. Based on the information provided, one can say: CHECK ALL THAT APPLY © STATS4STEM.ORG |
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B)
Which of the following statements are true about experimental design: A) Control refers to procedures or actions taken to reduce the effects of extraneous variables or lurking variables. B) In a randomized control experiment, the Control Group gets a treatment that will have no effect (placebo). C) If researchers were conducting a study on medication to reduce the risk of heart attacks and the pre-study survey showed that there were two groups: one group ate well and exercised often, while the second group had poor eating habits and were sedentary; in this situation, creating two blocks for each group would be a good idea as the lifestyle habits would most definetly have an effect on the response variable. D) Replication refers to the process of assigning each individual treatment to many experimental units or subjects. |
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