Data

Question 0

What is the formula triangle to calculate frequency density ?

Answer 0

Frequency

Frequency densityX group width

Question 1

If you have a question on box plots, what do you always talk about?

Answer 1

The median and relate it to the question e.t. On average…did better.

The IQR which group is the most consistent.

Question 2

How do you draw the frequency polygon ?

Answer 2

Plot the midpoint of each group with the frequency and connect the points with straight lines.
Don’t connect the first point with the origin.

Question 3

What is meant by a random sample ?

Answer 3

Each member of the population has an equal chance of selection.

Question 4

If you have a cumulative frequency graph and need to find the number of things above or below a certain thing on the X axis, what do you do?

Answer 4

Draw a line from the point you want on the X axis up to the cumulative frequency line. Then from this point, draw a horizontal line to the Y axis.
If you need to find the number of things below a value, this is your answer.
If you want to find the number of vales above, remove the answer you got from the total.

Question 5

What is a stratified sample?

Answer 5

The number from each group is proportional to the number in the population.