Module 2 - Descriptive Statistics

Question 1

What 3 popular measures are used to workout the central location or average?

Answer 1

1. The mean
2. The median
3. The mode

Question 2

Define mean?

Answer 2

The average

Question 3

Define median?

Answer 3

The middle value of a set of observations when they are arranged in order of magnitude

Question 4

Define mode?

Answer 4

The most frequently occurring value in a set of data

Question 5

What 4 measures are used to workout the dispersion or variability?

Answer 5

1. Range
2. Variance
3. Standard deviation
4. Coefficient of variation

Question 6

Define range?

Answer 6

The difference between largest and smallest observations

Question 7

Define variance?

Answer 7

A measure of variability of a numerical data set

Question 8

Define standard deviation?

Answer 8

Square root of the variance

Question 9

Define coefficient of variation?

Answer 9

Standard deviation divided by the mean

Question 10

Describe Chebyshev’s theorem?

Answer 10

describes how the mean and the standard deviation of a set of observations can be combined to determine the minimum proportion of observations that lie within various intervals centred at the mean

Question 11

Describe the empirical rule?

Answer 11

When the distribution is bell shaped, the percentage of observations that fall within 1, 2 and 3 standard deviations (SDs) from the mean are 68%, 95% and 99.7%, respectively