# Shared Flashcard Set

## Details

Stats 210 Final
Final
48
Accounting
04/30/2013

Term
 What is a way that Sensitivity is defined? a. 1- Sensitivity b. 1- False Negative Rate c. 1-Specificity d. Unable to determine it numerically
Definition
 B.
Term
 What would it mean for a home pregnancy test (HPT) to have good sensitivity? a. Means the test likely says youre pregnant when you are b.Means the test likely says you arent pregnant when you are c. Means the test likely says youre pregnant when you arent d. Means the test likely says you arent pregnant when you arent.
Definition
 A.
Term
 Identify the different scenarios in this Drug Test: Reality-
Definition
 How many people test and the results
Term
 Identify the different scenarios in this Drug Test: Test-
Definition
 Drug Test
Term
 Identify the different scenarios in this Drug Test: Sensitivity-
Definition
 The positive test and you take drugs
Term
 Identify the different scenarios in this Drug Test: Specificity-
Definition
 The test is negative and you dont do drugs
Term
 Identify the different scenarios in this Drug Test: False Negative-
Definition
 Test comes back negative but person is using drugs
Term
 Identify the different scenarios in this Drug Test: False Positive-
Definition
 Test comes back positive but person isnt using drugs
Term
 Identify the different scenarios in this Drug Test: Which is the worst?
Definition
 False positive, cause they think you are using drugs when you really are not
Term
 Sensitivity-
Definition
 This occurs when the reality is a positive and the test is positive
Term
 Specificity-
Definition
 This occrs when the reality is a negative and the test is also a negative
Term
 False Negative-
Definition
 this occurs when in reality the patient is positive but the test comes back negative
Term
 False Positive-
Definition
 this occurs when in reality the patient is negative but the test comes back positive
Term
 In the context of hypothesis testing, good sensitivity speaks to:  a. The ability of the test to reject a false HO b. The ability of the test to be very specific about what it is testing for c. The ability of the test to reject an HO that is true d. The ability of the test to not reject an HO that is true
Definition
 A.
Term
 If we are testing the null hypothesis HO:p<0.90 versus HA: p>0.90 and we compute z to be 1.8, then: a. we have statistically significant results, with an estimated false positive rate that is less than 0.05 b. we fail to have statistically significant results, with an estimated false positive that is less than 0.05 c. we have convincing evidence that p is >.90 d. we fail to have convincing evidence that p is >.90
Definition
 A
Term
 An experiment is done to compare two methods of instruction, Method A and Method B. At the end of the experiment a statistian reports that if one rejects the hypothesis that the two methods are the same, in favor of the alternative that they are different, then the false positive rate of that rule will be about 2 in 100. This means: a. You can be certain the methods are different b. you can be certain the methods are not different c. The methods are probably different d. The methods are probably not different
Definition
 c.
Term
 A given test is known to have a sensitivity of 90%. What does this tell you about the specificity? a. the specificity is 90% b. The specificity is 10% c. Not much, the specificity could be anywhere between 5% and 95% d. Nothing, the specificity could be anything
Definition
 d
Term
 In general what do you think is preferred for medical screening tests and why? a. High sensitivity-so patients without the disease can be correctly identified b. High Sensitivity-so patients with the disease can be correctly identified c. Low specificity-so patients without the disease can be correctly identified d. High specificity-so patients with the disease can be correctly identified
Definition
 b.
Term
 Refer to the work we have done with FST data in class.  Suppose you changed your rule to require that the total FST score required you to say you were drunk was 6 or above instead of 2 or above. What will happen to the specificity of your rule? a. it will increase b. it will decrease c. It will stay the same d. cant predict what will happen
Definition
 A
Term
 A test for prostate cancer in men is known to have a sensitivity of 97% and a specificity of 95%. If i were to test positive, what would be the probability of me having prostate cancer? a. 95% b. 97% c.<5% d. Depends on the prevalence of prostate cancer among all males
Definition
 D.
Term
 Refer to the work we have done with field sobriety test data in class. Suppose you changed your rule to require that the total FST score required to say you were drunk was 8 or above instead of 4 or above. What will happen to the specificity of your rule? a. It increases b. It decreases c. It stays the same d. Can't predict what will happen
Definition
 A
Term
 In our class this semester, what did we mean when we said the results of a certain test were statistically significant? a. We meant we had been able to reject HO with a false negative rate that was tolerable ( usually below 0.05) b. We meant we had been able to reject HA with a false positive rate that was tolerable( usually below 0.05) c. We meant we had been able to reject HO with a false positive rate that was tolerable( usually below 0.05) d. We meant we had been able to reject HA with a false negative rate that was tolerable (usually below 0.05)
Definition
 c
Term
 Which of the following is the correct interpretation of a p-value (with value x)? a. Given HO is true, there is probability x that we would obtain the data we got or data more extreme b. Give HA is true, there is probability x that we would obtain the data we got or data more extreme c. Given HO is true, there is probability 1-x that we would obtain the data we got or data more extreme d. Given HA is true, there is a probability 1-x that we would obtain the data we got or data more extreme
Definition
 A.
Term
 In words specificity is: a. The ability to correctly identify true positives b. The ability to correctly identify true negatives c. The ability to incorrectly identify true positives d. The ability to incorrectly identify true negatives
Definition
 B
Term
 In this situation, the 700 new mothers form the a. population b. sample c.statistic d. parameter
Definition
 B
Term
 In this situation, the percentage of all US mothers who breastfeed their infants is the a. population b. sample c. statistic d. parameter
Definition
 D
Term
 What can one say about the sampling distribution of a sample statistic based on a simple random sample? a. It is about bell-shaped and peaks above the parameter b. It is usually skewed if the population is not bell-shaped c. it is about bell-shaped and peaks above the statistic d. nothing can be said in advance about the sampling distribution since the sampling was random
Definition
 A.
Term
 A cattle farmer recently bought a new herd of cattle. He was interested in knowing the mean weight of his 35 new cows. When he told his wife that the mean was 1100 pounds, she asked what the margin error was.  The farmer argued that there is no need for one. Who was confused in this case? a. The wife because no specific confidence level was asked for. b. The farmer because only sampling variability is present c. The wife because there is no sample d. The farmer because he never took a stats class
Definition
 c.
Term
 Which of the following sources of error is addressed by the margin of error? a. sampling variability that comes from choosing a random sample b. errors in entering the data into the computer c. errors because some of the subjects did not understand the questions d. biases due to voluntary response
Definition
 a.
Term
 What is the purpose of a push poll? a. To spread negative information b. To see what kind of MOE will result c. To get quick results d. To see what kinds of themes and packages move the public
Definition
 A.
Term
 I want to take a random sample of this Stats 210 class. I assign each student a unique number based on their height. I then use a random number generator to pick 20 students. This is a random sample. a. True. As long as i dont ask a question about height, it is random b. True. Every possible sample had the same chance of being selected c. False. Some students were more likely than others to be selected, depending on their height. d. False. I should sample from the entire university
Definition
 B.
Term
 I want to take a random sample of this Stats 210 class. I assign each student that came to class last tuesday a number and use a random number generator to select 20 students. This is a random sample a. True. I used a random number generator. b. True. Every possible sample had the same chance of being selected c. False. There was coverage error since not all students attended class. d. False. Some students were more likely than others to be selected, depending on their height
Definition
 C.
Term
 What is the main purpose of sampling?
Definition
 To get an accurate representation of how the population feels about an issue without actually polling the entire population
Term
 Why do we want a random sample?
Definition
 So that the sample does not contain bias or any other error.
Term
 What must be true of each possible sample if the process of sampling is to be considered "random"
Definition
 Everyone should be given an equal chance to take the survey with the people being sampled to be random
Term
 What is a sampling distribution ?
Definition
 Sampling distribution is where you plot out the answers of your sample normally and it forms a bell shaped curve peaking over the parameter
Term
 How is it shaped?
Definition
 Shaped like a bell
Term
 Where is it centered?
Definition
 above the parameter
Term
 What is bias?
Definition
 When peoples opinions skew the results like if only certain people see it that support one way of the survey the others dont have a fair chance, unfair advantage
Term
 Inference-
Definition
 The act of drawing conclusions about something we cannot know for sure based on information we have to assume is accurate.
Term
 Confounding-
Definition
 can compromise the worth of our inferences
Term
 Response variable-
Definition
 variable measuring in experiment
Term
 Explanatory variable-
Definition
 what you change or alter
Term
 Lurking Variable-
Definition
 Variable not directly studied that can compromise your ability to attribute any changes in the response to a treatment
Term
 Cartoon
Definition
 Dilbert
Term
 Positive association-
Definition
 upward to right.
Term
 Negative association-
Definition
 downward to right
Term
 What constitutes a random sample?
Definition
 Everyone has an equal chance to take the survey and also the people chosen to take it must be picked at random
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