STAT 217 Cal Poly Questions with Correct Answers (Grade A+)
Question 1: BIG sample size for errors
Answer: makes TYPE 2 GREATER, no impact on type I
Question 2: Power
Answer: the probability we reject null hypothesis when null is false, we want HIGH probability ex:
probability of committing type 2 is 24%, so power is 76%
Question 3: bigger alpha value
Answer: -easier to reject null -easier to detect when null is false -HIGHER POWER
Question 4: sample size is bigger (power)
Answer: -sample statistics will be close to true value -HIGHER POWER
Question 5: scatterplots
Answer: -2 quantitative variables -direction (positive or negative) -form (linear?) -strength (R value)
Question 6: Random sampling
Answer: -draw conclusions about populations -reduce bias
Question 7: Random assignment
Answer: -establish cause and effect -use software to randomly divide treatments -create groups that are as
similar as possible -reduces CONFOUNDING
Question 8: y=mx+b
Answer: (response variable)=(y-intercept) + (slope) (explanatory variable)
Question 9: R^2
Answer: The % of variation in the response variable that can be accounted for by explanatory variable
Question 10: spread decreases as sample size...
Answer: gets BIGGER
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Question 1: BIG sample size for errors
Answer: makes TYPE 2 GREATER, no impact on type I
Question 2: Power
Answer: the probability we reject null hypothesis when null is false, we want HIGH probability ex:
probability of committing type 2 is 24%, so power is 76%
Question 3: bigger alpha value
Answer: -easier to reject null -easier to detect when null is false -HIGHER POWER
Question 4: sample size is bigger (power)
Answer: -sample statistics will be close to true value -HIGHER POWER
Question 5: scatterplots
Answer: -2 quantitative variables -direction (positive or negative) -form (linear?) -strength (R value)
Question 6: Random sampling
Answer: -draw conclusions about populations -reduce bias
Question 7: Random assignment
Answer: -establish cause and effect -use software to randomly divide treatments -create groups that are as
similar as possible -reduces CONFOUNDING
Question 8: y=mx+b
Answer: (response variable)=(y-intercept) + (slope) (explanatory variable)
Question 9: R^2
Answer: The % of variation in the response variable that can be accounted for by explanatory variable
Question 10: spread decreases as sample size...
Answer: gets BIGGER
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