Statistics

Question 1

Variance

Answer 1

(sum of (x-mean)²)/ (n-1)

Question 2

Standard Deviation

Answer 2

= Square Root of Variance

Question 3

Standard Error of the Mean

Answer 3

= Standard Deviation / v(n-1)

Question 4

Sensitivity

Answer 4

= True Positive/ True Positive + False Negative

Question 5

Specificity

Answer 5

= True Negative / True Negative + False Positive

Question 6

Positive Predictive Value

Answer 6

= True Positive / True Positive + False Positive

Question 7

Negative Predictive Value

Answer 7

True Negative/ True Negative + False Negative

Question 8

Which Statistical Test To Use

Normal Distribution (2x groups)

Answer 8

t-test

Unpaired- 2x groups

Paired- subject is both control and experiment

Question 9

Which Statistical Test To Use

Normal Distribution (3 or more groups)

Answer 9

Multiple t-test (the more t-tests the more chance of error see Bonferoni correction)

ANOVA- Analysis of the variance

Question 10

Which Statistical Test To Use

Non- Normal Distribution (2x groups)

Answer 10

Mann-Whitney

Wilcoxian

Question 11

Which Statistical Test To Use

Non-Normal Distribution (3 or more groups)

Answer 11

Kruskal-Wallis

Question 12

Which Statistical Test To Use

Qualitative Data

Answer 12

Chi-Squared Test

Fischer Exact Test (if numbers are very small)