DTSA 5002 - Statistical Inference and Hypothesis in Data
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1. Hypothesis testing
- Correct Answer: a decision-making process for evaluating claims about a
population
2. Hypothesis Testing Steps - Correct Answer: 1. specify null and alternative
2. choose an appropriate statistical test
3. specify the significant level (A) (.05)
4. obtain p value from test
5. compare p value with A and make a conclusion.
3. Type 1 Error
- Correct Answer: Rejecting null hypothesis when it is true
4. Type 2 error
- Correct Answer: failing to reject a false null hypothesis
5. Level of significance
- Correct Answer: the probability of making a type I error
6. Your friend Chip claims to have psychic abilities, and "superhuman predictive
skills." To test thistheory, you create an experiment with coins, where Chip
guesses the result of the flip, then you flipthe coin, and record whether he was
right. Assume the coin is fair. Let p be the proportion of flips that are guessed
correctly. From the list below, whichnull and alternative hypotheses are associated
,with Chip being better at predicting than a normal
person?
1. H0 : p = 0; H1 : p < 0
2. H0 : p = 0; H1 : p > 0
3. H0 : p = 1/2; H1 : p > 1/2
4. H0 : p = 1/2; H1 : p < 1/2
- Correct Answer: 3. H0 : p = 1/2; H1 : p > 1/2
7. There are four possibilities for the result of the test:
1. The test indicates that Chip is psychic, and in reality Chip is psychic.
2. The test indicates that Chip is psychic, and in reality, Chip is not psychic.
3. The test indicates that Chip is not psychic, and in reality Chip is psychic.
4. The test indicates that Chip is not psychic, and in reality Chip is not psychic.
a. We correctly reject the null hypothesis. (Choice 1)
b. We correctly fail to reject the null hypothesis. (Choice 2)
c. We commit Type I error. (Choice 3)
d. We commit Type II error. (Choice 4)
8. Over the last few weeks, you have gone birdwatching at your local park and
recording the number of distinct bird species that you saw each day. Your
recorded counts where (11; 6; 10; 7; 6; 9; 12; 11; 11).
However, when walking through the park, you found a sign which stated that
visitors should onlyexpect to see 8 bird species each day.
Use hypothesis testing to determine whether this claim is accurate, based on the
data you've seen.
Use a significance level of = 0:05. Assume all random variables are normally
distributed, and that the true standard deviation of bird species is 2. Save TRUE if
you reject the null hypothesis, and FALSE if you fail to reject the null hypothesis.
,- Correct Answer: TRUE
9. Your friend Chip claims to have "superhuman predictive skills." To test his
claims, you decide to set up an experiment with coins, where Chip will guess the
result of the flip, then you will flip the coin and record whether Chip guessed
correctly. Assume all coins are fair.
Let p be the proportion of flips that are guessed correctly. In the assignment for
module 1, we
discerned the null and alternative hypotheses to be:
H0 : p = 1/2
- Correct Answer: H1 : p > 1/2
Suppose we want to perform our hypothesis test at a significance level = 0:05.
Which
type of test will we perform and which critical region should we use?
1. Upper Tailed Test with critical region above z0:05.
2. Upper Tailed Test with critical region above z0:95.
3. Lower Tailed Test with critical region below z0:05.
4. Lower Tailed Test with critical region below z0:95.
5. None of the above.
- Correct Answer: 1. Upper Tailed Test with critical region above z0:05.
10. You and Chip sit down, perform the experiment, and find that Chip correctly
predicted
the results of 60 out of 100 flips. At the = 0:05 significance level, would the test
indicate that
Chip is or is not psychic?
- Correct Answer: TRUE
, 11. Suppose that the null hypothesis is actually false. If we where to decrease the
significance
level to = 0:01, what would happen to the power and to the probability of a Type
II error?
1. Both the power and the probability of Type II error would increase.
2. Both the power and the probability of Type II error would decrease.
3. The power would increase and the probability of Type II error would decrease.
4. The power would decrease and the probability of Type II error would increase.
- Correct Answer: 4. The power would decrease and the probability of Type II
error would increase.
12. You want to determine if cars from Plant B actually have a shorter life
expectancy than
those from Plant A. Let be the true mean life expectancy of cars from Plant B.
From the list
below, which is the correct hypothesis test for this situation?
1. H0 : = 220 H1 : < 220
2. H0 : = 220 H1 != 220
3. H0 : = 250 H1 : < 250
4. H0 : = 250 H1 != 250
5. None of the above.
- Correct Answer: 3. H0 : = 250 H1 : < 250
13. Suppose that we have not yet collected information on cars from plant B, but
still know
the values for cars from Plant A. Which of the situations below would result in the
test with the
highest power?
Science Comprehensive Resource To Help You Ace 2026-
2027 Exams Includes Frequently Tested Questions With
ELABORATED 100% Correct COMPLETE SOLUTIONS
Guaranteed Pass First Attempt!! Current Update!!
Instant Download Pdf
1. Hypothesis testing
- Correct Answer: a decision-making process for evaluating claims about a
population
2. Hypothesis Testing Steps - Correct Answer: 1. specify null and alternative
2. choose an appropriate statistical test
3. specify the significant level (A) (.05)
4. obtain p value from test
5. compare p value with A and make a conclusion.
3. Type 1 Error
- Correct Answer: Rejecting null hypothesis when it is true
4. Type 2 error
- Correct Answer: failing to reject a false null hypothesis
5. Level of significance
- Correct Answer: the probability of making a type I error
6. Your friend Chip claims to have psychic abilities, and "superhuman predictive
skills." To test thistheory, you create an experiment with coins, where Chip
guesses the result of the flip, then you flipthe coin, and record whether he was
right. Assume the coin is fair. Let p be the proportion of flips that are guessed
correctly. From the list below, whichnull and alternative hypotheses are associated
,with Chip being better at predicting than a normal
person?
1. H0 : p = 0; H1 : p < 0
2. H0 : p = 0; H1 : p > 0
3. H0 : p = 1/2; H1 : p > 1/2
4. H0 : p = 1/2; H1 : p < 1/2
- Correct Answer: 3. H0 : p = 1/2; H1 : p > 1/2
7. There are four possibilities for the result of the test:
1. The test indicates that Chip is psychic, and in reality Chip is psychic.
2. The test indicates that Chip is psychic, and in reality, Chip is not psychic.
3. The test indicates that Chip is not psychic, and in reality Chip is psychic.
4. The test indicates that Chip is not psychic, and in reality Chip is not psychic.
a. We correctly reject the null hypothesis. (Choice 1)
b. We correctly fail to reject the null hypothesis. (Choice 2)
c. We commit Type I error. (Choice 3)
d. We commit Type II error. (Choice 4)
8. Over the last few weeks, you have gone birdwatching at your local park and
recording the number of distinct bird species that you saw each day. Your
recorded counts where (11; 6; 10; 7; 6; 9; 12; 11; 11).
However, when walking through the park, you found a sign which stated that
visitors should onlyexpect to see 8 bird species each day.
Use hypothesis testing to determine whether this claim is accurate, based on the
data you've seen.
Use a significance level of = 0:05. Assume all random variables are normally
distributed, and that the true standard deviation of bird species is 2. Save TRUE if
you reject the null hypothesis, and FALSE if you fail to reject the null hypothesis.
,- Correct Answer: TRUE
9. Your friend Chip claims to have "superhuman predictive skills." To test his
claims, you decide to set up an experiment with coins, where Chip will guess the
result of the flip, then you will flip the coin and record whether Chip guessed
correctly. Assume all coins are fair.
Let p be the proportion of flips that are guessed correctly. In the assignment for
module 1, we
discerned the null and alternative hypotheses to be:
H0 : p = 1/2
- Correct Answer: H1 : p > 1/2
Suppose we want to perform our hypothesis test at a significance level = 0:05.
Which
type of test will we perform and which critical region should we use?
1. Upper Tailed Test with critical region above z0:05.
2. Upper Tailed Test with critical region above z0:95.
3. Lower Tailed Test with critical region below z0:05.
4. Lower Tailed Test with critical region below z0:95.
5. None of the above.
- Correct Answer: 1. Upper Tailed Test with critical region above z0:05.
10. You and Chip sit down, perform the experiment, and find that Chip correctly
predicted
the results of 60 out of 100 flips. At the = 0:05 significance level, would the test
indicate that
Chip is or is not psychic?
- Correct Answer: TRUE
, 11. Suppose that the null hypothesis is actually false. If we where to decrease the
significance
level to = 0:01, what would happen to the power and to the probability of a Type
II error?
1. Both the power and the probability of Type II error would increase.
2. Both the power and the probability of Type II error would decrease.
3. The power would increase and the probability of Type II error would decrease.
4. The power would decrease and the probability of Type II error would increase.
- Correct Answer: 4. The power would decrease and the probability of Type II
error would increase.
12. You want to determine if cars from Plant B actually have a shorter life
expectancy than
those from Plant A. Let be the true mean life expectancy of cars from Plant B.
From the list
below, which is the correct hypothesis test for this situation?
1. H0 : = 220 H1 : < 220
2. H0 : = 220 H1 != 220
3. H0 : = 250 H1 : < 250
4. H0 : = 250 H1 != 250
5. None of the above.
- Correct Answer: 3. H0 : = 250 H1 : < 250
13. Suppose that we have not yet collected information on cars from plant B, but
still know
the values for cars from Plant A. Which of the situations below would result in the
test with the
highest power?
