Statistics quiz

What is statistics?

• The study of numbers in isolation

• The use of complex equations to solve any problem

• The collection, analysis, and interpretation of data

• A branch of physics

Which of the following is an example of discrete data?

• Height of students

• Number of cars in a parking lot

• Weight of a person

• Temperature

Answer explanation

Whole number counts (like 5 or 12 cars) are discrete because they cannot be broken into fractions.

What is a sample?

• A portion of the population selected for analysis

• The entire set of data in a study

• A type of statistical test

• A numerical summary of data

Answer explanation

A sample is a smaller group taken from the population to analyze its characteristics without studying everyone.

What type of data is "height in centimeters"?

• Qualitative

• Continuous

• Discrete

• Categorical

Answer explanation

Height can take any value within a range (e.g., 170.5 cm), making it continuous data.

If a dataset has no repeated numbers, what is its mode?

• The smallest number

• The largest number

• There is no mode

• The middle number

Answer explanation

If all numbers are unique, no value appears more frequently, so there is no mode.

If all values in a dataset are the same, what is the standard deviation?

• 0

• 1

• Equal to the mean

• Very large

Answer explanation

If all values are the same, there’s no variability, so the standard deviation is 0.

If the average age of a group is 30 years, and a 50-year-old person joins the group, what happens to the mean age?

• It becomes 50

• It decreases

• It stays the same

• It increases

Answer explanation

Adding a higher value raises the average.

A histogram is used to show:

• Categories of data

• The distribution of numerical data

• Only whole numbers

• The probability of an event

Answer explanation

Histograms group numerical data into bins to show frequency distributions.

If two variables increase together, their correlation is:

• Negative

• Zero

• Positive

• Undefined

Answer explanation

If two variables increase together (e.g., study time and test scores), correlation is positive.

Probability is always between:

• -1 and 1

• 0 and 1

• 1 and 100

• 0 and infinity

Answer explanation

Probabilities range from 0 (impossible event) to 1 (certain event).