Stats

Question 1

The standard error measures the …

Answer 1

precision of the sample mean.

Question 2

The chi-square test is a nonparametric test to compare …

Answer 2

nominal or ordinal data comprising of one to multiple sample tests.

Question 3

The approximate percentage of data that is greater than one standard deviation to the right/left?

Answer 3

There is an additional 0.2% beyond 3 standard deviations. Therefore, 15.9% of data will be greater than one standard deviation (σ) to the right of the mean (μ).

This is calculated by 13.6% (1 to 2 σ) plus 2.1% (2 to 3 σ) plus 0.2% (> 3 σ). Often, numerical answers will be rounded to the nearest whole number (16%), particularly if the question asks for an approximation.

Question 4

Standard error of the mean is equal to …

Answer 4

the standard deviation divided by the square root of the sample size. If standard deviation is 1 and population size is 100, then SEM = 0.1.

Question 5

A type I error is

Answer 5

incorrectly accepting A type I error is incorrectly accepting Ha. (False positive)

Question 6

Type II or β error =

Answer 6

incorrectly accepting null hypothesis Ho. (false negative)

Question 7

Analysis of variance (ANOVA) is used to test …

Answer 7

parametric continuous data when 3 or more groups exist.

Question 8

Paired t-test vs unpaired t-test?

Answer 8

A paired t-test compares outcomes in a single group who serve as their own control, whereas an unpaired t-test compares an outcome in two different groups.

Question 9

Factors effecting type 2 error?

Answer 9

• As the alpha number is lowered, the chance of a Type I error is lowered, but the risk of a Type II error increases.
• As the difference between the two groups increases, there is less of a chance to obtain a Type II error.
• Increasing the number of data points within the experiment decreases the risk of a Type II error.
• variability of population is increased, the risk of a Type II error is increased.