Statistics Quiz

What is the purpose of descriptive statistics?

• To infer conclusions about a population

• To summarise and describe the main features of a dataset

• To identify relationships between variables

• To validate predictive models

Which of the following is NOT a measure of central tendency?

• Mean

• Median

• Range

• Mode

Variance and standard deviation both measure variability. How do they differ?

• Variance is expressed in the same units as the original data; standard deviation is squared.

• Standard deviation is expressed in the same units as the original data; variance is squared.

• Variance measures the spread; standard deviation measures central tendency.

• They are mathematically identical.

What is the null hypothesis (H₀) in hypothesis testing?

• A statement suggesting a significant effect or difference

• A prediction about the population

• A statement suggesting no effect or difference

• A formula to calculate confidence intervals

What does a p-value less than 0.05 indicate in hypothesis testing?

• The null hypothesis is true.

• There is no significant difference in the data.

• There is strong evidence against the null hypothesis.

• The sample size is too small.

What is the formula for a 95% confidence interval?

• Mean ± (1.96 × Standard Error)

• Mean ± (1.5 × Standard Deviation)

• Median ± (1.96 × Variance)

• Mean ± (2 × Range)

Which Excel function is used to calculate the standard deviation?

• =AVERAGE

• =STDEV

• =VAR

• =MEDIAN

What does the COUNTIF function do?

• Counts all non-empty cells in a range

• Counts empty cells in a range

• Counts cells that meet a specific condition

• Counts the largest value in a range

Which Excel function calculates the correlation coefficient?

• =VAR

• =CORREL

• =STDEV

• =COUNTIF

What does the chi-squared test of independence assess?

• Whether a variable follows a normal distribution

• The relationship between two categorical variables

• The goodness-of-fit for a data distribution

• The variability within a sample