Hypothesis Test for a Population Mean

Suppose your p-value is .10. What is your conclusion? a. Reject Ho b. Fail to Reject Ho

b. Fail to Reject Ho

A two-tailed hypothesis test (meaning Ha is μ ≠ μo) is related to a confidence interval. If thevalue in H0 is not in the confidence interval, it means you ____________ H0 a. reject b. fail to reject

a. reject

Suppose you are doing a hypothesis test where your hypotheses are Ho: u = 10 vs Ha: u > 10,and your test statistic is equal to 2.87. What is the p-value? a. 4979 b. .0021 c. .9979 d. None of the above

b. .0021

If you have enough evidence against H0 and you are able to reject it, your p-value must havebeen: a. Small b. Large

a. Small

Bob's alternative hypothesis is Ha: u > 8 and his test statistic is 1.75. What is Bob's p-value? a. 0.9599 b. 0.4599 c. 0.0401 d. 0.0802

c. 0.0401

Suppose it's reported that the average gas price in Ohio is $2.10 per gallon. You believe it'slower than that. Your random sample of 100 gas stations in Ohio has an average gas price of$1.98 per gallon. What is your alternative hypothesis? a. Ho: 𝜇𝑥 = $2.10 b. Ho: 𝜇𝑥 > $2.10 c. Ho: 𝝁𝒙 < 𝟐.𝟏𝟎 d. Ho: 𝜇𝑥 < 1.98

c. Ho: 𝝁𝒙 < 𝟐.𝟏𝟎

What is the name for the cutoff value that lets you decide between rejecting Ho and failing to reject Ho with your p-value? a. Z-level b. confidence level c. significance level d. None of the other choices is correct

c. significance level

Your friend claims the average price of a burger in the Columbus Gateway Area is $10.00. You believe it's lower than that. What symbol represents the $10 in this scenario? a. x-bar b. μX c. μo

c. μo

Bottles of cream have a normal distribution with mean 8 ounces. You would stop the process if the containers were being filled incorrectly. What is your alternative hypothesis? a. Ha: u > 8 b. Ha: u < 8 c. None of the other answers is correct. d. Ha: u not equal to 8

d. Ha: u not equal to 8

When you take the given information and form a Z-score in a hypothesis test for the mean, what is the special name of that result? a. None of the other choices is correct b. sample statistic c. descriptive statistic d. test statistic

d. test statistic

t/f: For a two-tailed hypothesis test (meaning Ha is μ≠μo) the further away your test statistic getsfrom 0 the larger your p-value gets

false

t/f: If your test statistic is negative, so is your p-value.

false

t/f: The p-value will change if you get a new data set.

false

t/f: The value of α will change if you get a new data set.

false

t/f: Failing to reject Ho and Accepting Ho are both appropriate conclusions that mean the same thing.

false: fail to reject or reject

t/f: The significance level is the same as a Type 2 error.

false: the chance of a type 1 error happening is = to the significance level

t/f: For a two-tailed hypothesis test (meaning Ha is μ ≠μo) the further away your test statistic getsfrom 0 the more likely it is that you will reject Ho

true

t/f: If Ha is not equals, you have to double the probability of being beyond your test statistic to get your p-value.

true

t/f: If you reject Ho in a hypothesis test for the mean, the value of uo is guaranteed not to be in the corresponding confidence interval. (Assume Ha is , alpha = .05, confidence level = 95%)

true

t/f: A Type 2 error is described as a false alarm.

false

Yogurt containers are supposed to have a mean fill amount of 8 ounces. You believe thecontainers are under filled. What are the null and alternative hypotheses? a. H0: μ = 8 and HA: μ < 8 b. H0: μ < 8 and HA: μ ≥ 8 c. H0: Xbar =8 and HA: 𝑥 < 8 d. None of the above

a. H0: μ = 8 and HA: μ < 8

The p-value changes if you obtain a new data set, but the significance level stays the same. a. True b. False

a. True

If your p-value is .11, and the significance level is .05, what do you conclude? a. Not enough information to tell b. Fail to reject Ho c. Reject Ho

b. Fail to reject Ho

Suppose it's reported that the average gas price in Ohio is $2.10 per gallon. You believe it'slower than that. Your random sample of 100 gas stations in Ohio has an average gas price of$1.98 per gallon. What is your null hypothesis? a. Ho: 𝝁𝑿 = $𝟐.𝟏𝟎 b. Ho: 𝜇𝑋 > $2.10 c. Ho: 𝜇𝑋 = $2.20 d. None of the above

a. Ho: 𝝁𝑿 = $𝟐.𝟏𝟎

If you reject Ho, which type of error could you be making? a. Type 1 error b. Could make both Type 1 and Type 2 errors c. No error is made, your conclusion is correct. d. Type 2 error

a. Type 1 error

Suppose someone reports that the average age of all Pokemon players is 13. You believe it's higher than that because your statistics professor plays Pokemon. You decide to challenge the claim. Do you use a confidence interval or a hypothesis test? a. hypothesis test b. confidence interval c. either a hypothesis test or a confidence interval

a. hypothesis test

Bottles of cream have a normal distribution with mean 8 ounces. You would stop the process if the containers were being filled incorrectly. Your sample of 30 containers has an average weight of 7.7 ounces. Assume the standard deviation is .8. What is your test statistic? a. 7.7 b. -2.05 c. None of the other choices is correct d. -.375 e. 2.05

b. -2.05: test statistic is your z value

Suppose you want to estimate the average age of all Pokemon players. Would you use a confidence interval or a hypothesis test? a. A hypothesis test b. A confidence interval

b. A confidence interval

The p-value is pre-set and known before the hypothesis test is conducted, but the significancelevel is unknown until the data has been collected. a. True b. False

b. False

Suppose someone claims the average delivery time for U.S. packages to be delivered during December is 2 days. You believe it takes longer than that. You conduct a hypothesis test; what are your hypotheses? a. Ho: X-bar = 2 vs. Ha: X-bar ≠ 2 b. Ho: µ = 2 vs. Ha: µ >2 c. Ho: µ >2 vs. Ha: µ ≤ 2 d. Ho: X-bar = 2 vs. Ha: X-bar > 2

b. Ho: µ = 2 vs. Ha: µ >2

Suppose it's reported that the average gas price in Ohio is $2.10 per gallon. You believe it'slower than that. Your random sample of 100 gas stations in Ohio has an average gas price of$1.98 per gallon. Assume the standard deviation of all gas prices is .50. What is the test statistic? a. 1.98 b. 2.40 c. -2.40 d. None of the above

c. -2.40

In testing the hypotheses Ho: µ = 800 vs Ha: µ≠800, if the value of the test statistic equals 1.75, then the p-value is: a. 0.9599 b. 0.0401 c. 0.0802 d. None of the other choices is correct

c. 0.0802