COURSE 4: THE POWER OF STATISTICS

Introduction to Hypothesis Testing

PRACTICE QUIZ: TEST YOUR KNOWLEDGE: INTRODUCTION TO HYPOTHESIS TESTING

1. Fill in the blank: The _____ typically assumes that observed data does not occur by chance.

2. Which of the following statements describe significance level? Select all that apply.  

3. What concept refers to the probability of observing results that are at least as extreme as those observed when the null hypothesis is true?  

4. A data professional conducts a hypothesis test. They mistakenly conclude that their result is statistically significant when it actually occurred by chance. What type of error does this scenario describe?  

PRACTICE QUIZ: TEST YOUR KNOWLEDGE: ONE-SAMPLE TESTS

1. In a one-sample hypothesis test, what does the null hypothesis state?  

2. A data professional conducts a hypothesis test. They discover that their p-value is less than the significance level. What conclusion should they draw?  

PRACTICE QUIZ: TEST YOUR KNOWLEDGE: TWO-SAMPLE TESTS

1. What does a two-sample hypothesis test determine?  

2. What is the null hypothesis of a two-sample t-test?

PRACTICE QUIZ: TEST YOUR KNOWLEDGE: HYPOTHESIS TESTING WITH PYTHON

1. A data professional can use the Python function scipy.stats.ttest_ind() to compute the p-value for the two-sample t-test.

2. What arguments of the Python function scipy.stats.ttest_ind(a, b, equal_var) refer to observations from the sample data? Select all that apply.

MODULE 5 CHALLENGE

1. Which of the following statements accurately describes the null hypothesis? Select all that apply. 

2. What term describes the probability of rejecting the null hypothesis when it is true?

3. A data professional conducts a hypothesis test. They fail to reject the null hypothesis. What statement best describes their conclusion?

4. A data professional conducts a hypothesis test. When they draw their conclusion, they commit a type I error. Which of the following statements describe their error? Select all that apply.

5.A data professional at an emergency response center conducts a hypothesis test to identify optimal ambulance routes. They just found the p-value. What should they do next? 

6. A data professional conducts a hypothesis test. They choose a significance level of 10%. They calculate a p-value of 12.4%. What conclusion should they draw?

7. A data professional is conducting a two-sample t-test. What does their alternative hypothesis state?

8. A data professional conducts a hypothesis test to compare the mean annual sales of two different restaurants in the same restaurant chain. They write the following code:

scipy.stats.ttest_ind(a=530, b=550, equal_var=FALSE)

What does the argument equal_var=FALSE refer to? 

9. Which of the following statements accurately describe the null hypothesis? Select all that apply. 

10. To draw a conclusion about the null hypothesis, what two concepts are compared?  

11. A data professional conducts a hypothesis test to compare the mean annual sales of two different restaurants in the same restaurant chain. They write the following code:

scipy.stats.ttest_ind(a=530, b=550, equal_var=FALSE) 

What does the argument a=530 refer to? 

12. What is the term for the arbitrary threshold determining whether an observed difference between groups occurred by chance?

13. A data professional conducts a hypothesis test. When they draw their conclusion, they fail to reject a null hypothesis, which is actually false. What type of error do they commit?

14. A data professional conducts a hypothesis test. They choose a significance level of 5%. They calculate a p-value of 3.3%. What conclusion should they draw?

15. In a one-sample hypothesis test of the mean, what are the typical options for the alternative hypothesis? Select all that apply.

16. A data professional conducts a hypothesis test. They choose a significance level of 1%. They calculate a p-value of 0.01%. What conclusion should they draw?

17. A data professional is conducting a hypothesis test. Their null hypothesis states that there is no difference between two population proportions. What type of test are they conducting?

18. What does the concept of p-value refer to?  

19. When would a data professional reject the null hypothesis?

20. A data professional on a marketing team conducts a hypothesis test to compare the mean time customers spend on two different versions of a company’s website. To start, they state the null hypothesis and the alternative hypothesis. What should they do next?

21.  A data professional conducts a hypothesis test to compare the mean annual sales of two different restaurants in the same restaurant chain. They write the following code:

scipy.stats.ttest_ind(a=530, b=550, equal_var=FALSE)

What does the argument b=550 refer to? 

22. A data professional conducts a hypothesis test. When they draw their conclusion, they commit a type II error. Which of the following statements accurately describe this scenario? Select all that apply.

23. A data analytics team in the landscaping industry conducts a hypothesis test to compare the effects of certain fertilizers on flower production. To start, they state the null hypothesis and the alternative hypothesis. Then they choose a significance level. What should they do next?

24. What type of hypothesis typically assumes that observed data does not occur by chance?  

25. The null hypothesis is a statement that is assumed to be true unless there is convincing evidence to the contrary. The null hypothesis typically assumes that observed data occurs by chance.  

26. What is the first step when conducting a hypothesis test?  

27. To compare two population means, a data professional uses a one-sample hypothesis test. 

CONCLUSION to Introduction to Hypothesis Testing