Biostat

Question 1

Skewed to the left

Answer 1

Outlying values are small
Mean is maller than the median
Mean < median < mode

Question 2

Skewed to the right

Answer 2

Outlying values are large
Mean is larger than the median
Mode < median < mean

Question 3

Level of significance

Answer 3

Denoted as alpha
Measure of strength of the evidence that must be present in your sample before you will reject the null hypothesis

a typically set at ≤0.05
Allows interpretation with 95% certainty that a detected association is true

Question 4

Z vs t test

Answer 4

Variance known —> z test

Variance unknown —> t-test

Question 5

Correlation

Answer 5

Expressed by the correlation coefficient “r”
Also termed Pearson correlation coefficient
Measures strength of association

Question 6

Regression

Answer 6

Allows for prediction of a dependent variable based on an independent (known) variable

Question 7

Nonparametric test of unpaired t test

Answer 7

Mann-Whitney U test

Question 8

Nonparametric test of paired t test

Answer 8

Wilcoxon matched pairs test

Question 9

P value

Answer 9

The probablity that the observed result is due to chane alone

If p < 0.01, there is less than a 1 in 100 chance of the detected ssociation being due to chance alone