Stat 217 midterm 2 Questions with Correct Answers (Grade A+)
Question 1: Null hypothesis
Answer: Ho M= Sets the population mean equal to a value
Question 2: Alternative hypothesis
Answer: Hypothesis testing the population mean not equal to a specific value (what you're trying to prove)
= prediction Ha M > x Ha M < x Ha M is not equal to x
Question 3: Test statistic formula
Answer: -refer as standard errors not standard deviation -sample SD not population SD -using a hypothesis
for population meanwe don't know if its true - use the sample mean for X
Question 4: How to interpret a T.S
Answer: The sample mean of ____ is _____ standard errors away from the population mean hypothesized
of ___
Question 5: P value
Answer: Probability of getting the sample data or more extreme data given the null hypothesis is true -
always in term of HA One tailinterested in one direction Two tailinterested in both
Question 6: Ha : M>X
Answer: Then our p-value is the probability of being greater than the T.S
Question 7: Ha: M<X
Answer: Then our p value is the probability of being smaller than the T.S
Question 8: Ha: M is not equal to X
Answer: p-value is the probability of being greater than the positive T.S. and less than the negative T.S.
Page 1
, Question 9: Alpha level
Answer: threshold level for a specific hypothesis test
Question 10: P value is less than alpha
Answer: to reject the null hypothesis and support the alternative
Question 11: p value is greater than alpha
Answer: fail to reject the null hypothesis and not support the alternative - fail to reject not accept!!!! - no
evidence to support
Question 12: How to interpret a p value
Answer: ___ % chance we would have gotten ____ test statistic or something _____ (bigger, smaller, or
bigger and smaller) than it
Question 13: Alpha
Answer: Threshold level which we will use to reject the null hypothesis if our p-value is lower than it.
Question 14: Smaller the error rate
Answer: The more difficult it will be to reject the null and support the alternative Standard alpha level= .05
or 5%
Question 15: Type 1 error (alpha)
Answer: Probability of rejecting the null hypothesis when it is in fact true (will mostly be concerned with
alpha)
Question 16: Type 11 error (beta)
Answer: Probability of failing to reject the null hypothesis when it is in fact false
Question 17: Ex of putting answer in terms of the problem
Answer: We have sufficient evidence to reject the claim that the population mean of snaps a Cal Poly
receives per day is 25. We have sufficient evidence that the mean amount of snaps a college student snap
chat user receives per day is greater than 25. - we don't have evidence if we don't support -comment on both
the null and the alternative
Page 2
Question 1: Null hypothesis
Answer: Ho M= Sets the population mean equal to a value
Question 2: Alternative hypothesis
Answer: Hypothesis testing the population mean not equal to a specific value (what you're trying to prove)
= prediction Ha M > x Ha M < x Ha M is not equal to x
Question 3: Test statistic formula
Answer: -refer as standard errors not standard deviation -sample SD not population SD -using a hypothesis
for population meanwe don't know if its true - use the sample mean for X
Question 4: How to interpret a T.S
Answer: The sample mean of ____ is _____ standard errors away from the population mean hypothesized
of ___
Question 5: P value
Answer: Probability of getting the sample data or more extreme data given the null hypothesis is true -
always in term of HA One tailinterested in one direction Two tailinterested in both
Question 6: Ha : M>X
Answer: Then our p-value is the probability of being greater than the T.S
Question 7: Ha: M<X
Answer: Then our p value is the probability of being smaller than the T.S
Question 8: Ha: M is not equal to X
Answer: p-value is the probability of being greater than the positive T.S. and less than the negative T.S.
Page 1
, Question 9: Alpha level
Answer: threshold level for a specific hypothesis test
Question 10: P value is less than alpha
Answer: to reject the null hypothesis and support the alternative
Question 11: p value is greater than alpha
Answer: fail to reject the null hypothesis and not support the alternative - fail to reject not accept!!!! - no
evidence to support
Question 12: How to interpret a p value
Answer: ___ % chance we would have gotten ____ test statistic or something _____ (bigger, smaller, or
bigger and smaller) than it
Question 13: Alpha
Answer: Threshold level which we will use to reject the null hypothesis if our p-value is lower than it.
Question 14: Smaller the error rate
Answer: The more difficult it will be to reject the null and support the alternative Standard alpha level= .05
or 5%
Question 15: Type 1 error (alpha)
Answer: Probability of rejecting the null hypothesis when it is in fact true (will mostly be concerned with
alpha)
Question 16: Type 11 error (beta)
Answer: Probability of failing to reject the null hypothesis when it is in fact false
Question 17: Ex of putting answer in terms of the problem
Answer: We have sufficient evidence to reject the claim that the population mean of snaps a Cal Poly
receives per day is 25. We have sufficient evidence that the mean amount of snaps a college student snap
chat user receives per day is greater than 25. - we don't have evidence if we don't support -comment on both
the null and the alternative
Page 2
