1) Problem #PRAJH7J "PRAJH7J - 245931 - What is true abou..." |
What is true about the Least-Squares Regression Line? © STATS4STEM.ORG |
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2) Problem #PRAJH7N "PRAJH7N - 245934 - Correlation measu..." |
Correlation measures: © STATS4STEM.ORG |
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3) Problem #PRAEVPY "PRAEVPY - 136855 - An article in USA..." |
A)
An article in USA Today stated that "Internal surveys paid for by directory assistance providers show that even the most accurate companies give out wrong numbers 15% of the time." Assume that you are testing such a provider by making 10 requests and also assume that the provider gives the wrong number 15% of the time. Round this and subsequent answers to the nearest hundred. a) Find the probability of getting one wrong number. © STATS4STEM.ORG |
B)
b) Find the probability of getting at most one wrong number. Round to the nearest hundred. |
4) Problem #PRAJNDE "PRAJNDE - STATS4STEM.ORG" |
A)
McGonalds Burger advertises a quarter pound (0.25 lb) cheesburger. A local burger lover feels that the burgers actually have less meat than advertised. To prove his claim, he randomly purchases 12 burgers and measures and records the weight in pounds. The data is below:0.19 0.23 0.30 0.22 0.24 0.23 0.23 0.22 0.29 0.21 0.23 0.23 What is the best formula to calculate the test statistic for this problem? A. B. C. D. © STATS4STEM.ORG |
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B)
What assumptions and condition must be checked before proceeding with your test of significance? |
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C)
Calculate the test statistic, t, for this problem. Round answer to the nearest hundredths. |
D)
Using either the TI-83 or R/Rweb, calculate the p-value. Round answer to the nearest hundredth. |
E)
State the conclusion in the context of the problem. |
F)
For this problem, calculate the margin of error for a 95% confidence interval. Round answer to the nearest hundredth. |
5) Problem #PRAJB75 "PRAJB75 - 240183 - As the p-value de..." |
As the p-value decreases. The strength against the null hypothesis: © STATS4STEM.ORG |
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6) Problem #PRAJNPH "PRAJNPH - 249278 - A speed reading c..." |
A)
A speed reading company claims that their product reduces the time it takes to read a page. To prove their claim, 12 random individuals were timed on their ability to read a page. This data was recorded as sample A. The individuals then took a two-day speed reading class offered by the company and were timed again after taking the class. Their second recorded time was recorded as sample B. To prove their claim, which of the following test statistics should be used? A. B. C. D. E. © STATS4STEM.ORG |
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B)
Calculate the test statistic, t. Round answer to the nearest hundredth. |
C)
Calculate the p-value for this hypothesis test. Round answer to the nearest hundredth. |
D)
Calculate the margin of error for a 99% confidence interval. Round answer to the nearest hundredth. |
7) Problem #PRAKBY7 "PRAKBY7 - 269759 - A thousand sample..." |
A)
A thousand samples of size n were drawn from a population to estimate an unknown parameter, p - the proportion of individuals in the population who text daily. The thousand recorded p-hats were used to create the sampling distribution for p-hat that is found below. Using the sampling distribution for p-hat, estimate p. © STATS4STEM.ORG |
B)
Because p is found at the center of the sampling distribution of p-hat, we can say that p-hat is a(n) _____________________________ estimator. |
C)
Through visual inspection of the sampling distribution shown above, estimate the standard deviation of the sampling distrion of p-hat. |
D)
Estimate the sample size of each individual sample to get the sampling distribution found above. Choose from the most appropriate answers found below. |
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8) Problem #PRAJ7GX "PRAJ7GX - 265442 - 157568 - Confidence intervals - proportions - sample size" |
A)
A researcher wishes to estimate the proportion of squirrels that can be classified as red squirrels in a national park. She wants to construct a 90% confident interval that has a margin of error of 5%. a) How large a sample should be taken if it is estimated that 10% of all squirrels are red squirrels in the national park? © STATS4STEM.ORG |
B)
b) If no estimate is available for the proportion of red squirrels in the national park, how large should the sample be? |
9) Problem #PRAKN89 "PRAKN89 - 279619 - A school principa..." |
A school principal wishes to conduct a study in his school about bullying. There are 6 grades in his school, grades 7-12. Grades 7 and 8 have much lower enrollment compared to the rest of the school. For the study, the principal wants to research the prevelance and effects of bullying by grade. For this study, the most appropriate method to collect data would be: © STATS4STEM.ORG |
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10) Problem #PRAKN9T "PRAKN9T - 279636 - A patient decides..." |
A patient decides to participate in a research study, but neither the doctor nor the patient knows which treatment is being administered. This can be best described as a: © STATS4STEM.ORG |
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11) Problem #PRAKN92 "PRAKN92 - 279643 - The basic princip..." |
The basic principles of experimental design include: © STATS4STEM.ORG |
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12) Problem #PRAJBDY "PRAJBDY - 239403 - An electronic chi..." |
A)
An electronic chip manufacturing company is hired by ACME Electronics Inc. to manufacture a complicated electronic chip for them. The manufacturing company charges a very high fee for each chip as they claim that the manufacturing process produces a high number of defects. In fact, the chip manufacturer claims that due to the unique chip design, 40 percent of the chips produced are defective. ACME is concerned that this may not be true. If the percentage defects are too high, then the company may be unreliable. If the percentage defects are too low, they may be paying too much for the chips as the company claims that the high defect rate is the reason for the high cost of the chip. They decide on a surprise inspection of the manufacturing company to test the manufacturing company's claim. Which is the correct hypothesis? A) Ho: p = .40 HA: p < .40 B) Ho: p-hat = .40 HA: p-hat ≠ .40 C) Ho: μ = .40 HA: μ ≠ .40 D) Ho: p=.40 HA: p≠.40 E) Ho: p-hat = .40 HA: p-hat < .40 © STATS4STEM.ORG |
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B)
Which equation should be used to calculate the test statistic? A) B) C) D) E) |
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C)
What conditions need to be checked? |
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D)
They take a simple random sample of 165 chips, of which 58 where found to be defective. Calculate the p-value. Round answer to the nearest hundredth. |
E)
If ACME wishes to use a significance level of 0.1, state the conclusion below: |
13) Problem #PRAE82W "PRAE82W - 147765 - Which statement i..." |
Which statement is correct? © STATS4STEM.ORG |
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