AQL Statistical Reasoning and Probability 2

Question 1

What is the difference between 'correlation' and 'causation'?

Accepted Answer

Correlation shows two variables move together; causation means one variable directly causes the other

Answer

Correlation means two variables tend to change together, but causation requires evidence that one variable directly produces a change in the other.

Question 2

In statistics, an 'outlier' is best described as:

Accepted Answer

A data point that is far removed from the rest of the data set

Answer

An outlier is an unusually high or low value relative to the rest of the data, which can significantly affect the mean and range of a data set.

Question 3

A bag contains 5 red marbles and 3 blue marbles. What is the probability of randomly selecting a blue marble?

Accepted Answer

3/8

Answer

There are 3 blue marbles and 8 total marbles (5 + 3), so the probability = 3/8.

Question 4

What does a 'sample' represent in statistical research?

Accepted Answer

A subset of the population selected for study

Answer

A sample is a smaller, selected subset of a larger population, used to make inferences about the whole group.

Question 5

Which measure of central tendency is most affected by extreme values (outliers)?

Accepted Answer

Mean

Answer

The mean is calculated using all data values, so a single extreme outlier can pull it significantly up or down, making it sensitive to outliers.

AQL - Academic and Quantitative Literacy Practice Test