Exam 1 Part 3

Question 1

Summarize a sample of data using graphs and numerical measures such as means or percentages

Answer 1

Descriptive Statistics

Question 2

Use the sample to reflect back on the population the sample represents

Answer 2

Inferential statistics

Question 3

What are the two main forms of statistical inferencing?

Answer 3

Confidence intervals, hypothesis testing

Question 4

Data is collected separately for both groups.

Answer 4

Independent samples

Question 5

Individuals are measured twice (e.g. before and after treatment), or individuals are matched in pairs (e.g. identical twins).

Answer 5

Dependent/Paired/Matched Samples

Question 6

The proportion of times an event will occur in the long run. Gives us the chance, or likelihood of that event occurring.

Answer 6

Probability of an event

Question 7

If the p-value is less than .05, what do we say?

Answer 7

There is sufficient evidence to support that there is a mean/median difference between ____ (Ha). We will reject H0.

Question 8

If the p-value is more than .05, what do we say?

Answer 8

There is insufficient evidence to support that there is a mean/median difference between _____ (Ha). We fail to reject H0.

Question 9

Error that occurs when we reject H0 when in fact H0 is true (i.e., conclude there is a significant result when in fact there is not).

Answer 9

Type I

Question 10

Error that occurs when we fail to reject H0 when in fact Ha is true (i.e., conclude the result is not significant when in fact a significant difference or relationship exists).

Answer 10

Type II

Question 11

The probability of rejecting H0 when in fact Ha is true (i.e., correctly conclude there is a significant difference).

Answer 11

Power of a test

Question 12

Name an example of a parametric test

Answer 12

Paired t-test

Question 13

Name an example of a non-parametric test

Answer 13

Wilcoxon signed rank test

Question 14

What statements are true about a parametric test?

Answer 14

First choice for interval/ratio data, must assume a normal population, sensitive to outliers

Question 15

What statements are true about a non-parametric test?

Answer 15

Our choice for I/R data if the normality assumption is not met, Do not need to make any assumptions about the population, Are based on ranks; not affected by outliers

Question 16

How are the hypotheses written for a paired t-test?

Answer 16

H0: The population mean difference is zero (there is no difference, on average)
Ha: The population mean difference is not zero (there is a difference, on average)

Question 17

How are hypotheses written for a Wilcoxon Signed Rank test?

Answer 17

H0: The population median difference is zero (no difference between before & after)
Ha: The population median difference is not zero (there is a difference between before & after)

Question 18

How would you write the hypotheses in the following situation (if it was a paired t-test): Was there a significant mean change in BMI from admission to discharge?

Answer 18

H0: There is no mean difference in BMI from admission to discharge.

Ha: There is a mean difference in BMI from admission to discharge.

Question 19

How would you write the hypotheses in the following situation (if it was a Wilcoxon signed rank test): Is there a significant (median) difference in duration of middle-ear effusion between breast-fed and bottle-fed babies

Answer 19

H0: There is no median difference in duration of middle-ear effusion between breast-fed and bottle-fed babies.

Ha: There is a median difference in duration of middle-ear effusion between breast-fed and bottle-fed babies.

Question 20

How are hypotheses written for a two sample t-test?

Answer 20

H0: The means of the two populations are equal
Ha: The means of the two populations differ