STA1610 – Introduction to Statistics | January/February 2026
Supplementary Exam Memo (UNISA South Africa)
,Question 1
What is the mean of the following data set?
3, 5, 7, 9, 11
• A) 5
• B) 7
• C) 8
• D) 9
Correct Option: B) 7
Rationale: The mean is calculated by adding all the numbers together and dividing by
the count of numbers.
3 + 5 + 7 + 9 + 11 35
Mean = = =7
5 5
Question 2
What is the purpose of a hypothesis test?
• A) To prove a hypothesis correct
• B) To determine if there is enough evidence to reject a null hypothesis
• C) To always accept the alternative hypothesis
• D) To calculate the mean of a population
Correct Option: B) To determine if there is enough evidence to reject a null
hypothesis
Rationale: A hypothesis test assesses the strength of evidence against a null
hypothesis, not to prove or accept any hypothesis.
Question 3
Which of the following represents the median of the data set?
4, 1, 7, 3, 9
• A) 3
• B) 4
• C) 5
• D) 7
,Correct Option: B) 4
Rationale: To find the median, the data must be sorted: 1, 3, 4, 7, 9. The median is the
middle value, which is 4.
Question 4
In a standard normal distribution, what is the mean?
• A) 0
• B) 1
• C) 0.5
• D) 10
Correct Option: A) 0
Rationale: The standard normal distribution has a mean of 0 and a standard deviation
of 1.
Question 5
Which of the following is a measure of variability?
• A) Mean
• B) Mode
• C) Range
• D) Median
Correct Option: C) Range
Rationale: The range measures the spread of the data by calculating the difference
between the maximum and minimum values.
Question 6
What is the mode of the following data set?
2, 4, 4, 6, 8, 8, 8, 10
• A) 4
• B) 6
• C) 8
• D) 10
, Correct Option: C) 8
Rationale: The mode is the number that appears most frequently. Here, 8 appears three
times.
Question 7
Which type of data is measured on a nominal scale?
• A) Age
• B) Temperature
• C) Gender
• D) Distance
Correct Option: C) Gender
Rationale: Nominal data represents categories without a specific order, such as
gender.
Question 8
What is the variance of the following data set?
5, 7, 3, 9
• A) 4
• B) 5
• C) 6
• D) 2
Correct Option: A) 4
Rationale: Variance is calculated by finding the mean, subtracting each value from the
mean, squaring the results, and averaging those squared differences.
Question 9
If the p-value is less than the significance level (α), what should you do?
• A) Fail to reject the null hypothesis
• B) Accept the null hypothesis
• C) Reject the null hypothesis
• D) Collect more data
Supplementary Exam Memo (UNISA South Africa)
,Question 1
What is the mean of the following data set?
3, 5, 7, 9, 11
• A) 5
• B) 7
• C) 8
• D) 9
Correct Option: B) 7
Rationale: The mean is calculated by adding all the numbers together and dividing by
the count of numbers.
3 + 5 + 7 + 9 + 11 35
Mean = = =7
5 5
Question 2
What is the purpose of a hypothesis test?
• A) To prove a hypothesis correct
• B) To determine if there is enough evidence to reject a null hypothesis
• C) To always accept the alternative hypothesis
• D) To calculate the mean of a population
Correct Option: B) To determine if there is enough evidence to reject a null
hypothesis
Rationale: A hypothesis test assesses the strength of evidence against a null
hypothesis, not to prove or accept any hypothesis.
Question 3
Which of the following represents the median of the data set?
4, 1, 7, 3, 9
• A) 3
• B) 4
• C) 5
• D) 7
,Correct Option: B) 4
Rationale: To find the median, the data must be sorted: 1, 3, 4, 7, 9. The median is the
middle value, which is 4.
Question 4
In a standard normal distribution, what is the mean?
• A) 0
• B) 1
• C) 0.5
• D) 10
Correct Option: A) 0
Rationale: The standard normal distribution has a mean of 0 and a standard deviation
of 1.
Question 5
Which of the following is a measure of variability?
• A) Mean
• B) Mode
• C) Range
• D) Median
Correct Option: C) Range
Rationale: The range measures the spread of the data by calculating the difference
between the maximum and minimum values.
Question 6
What is the mode of the following data set?
2, 4, 4, 6, 8, 8, 8, 10
• A) 4
• B) 6
• C) 8
• D) 10
, Correct Option: C) 8
Rationale: The mode is the number that appears most frequently. Here, 8 appears three
times.
Question 7
Which type of data is measured on a nominal scale?
• A) Age
• B) Temperature
• C) Gender
• D) Distance
Correct Option: C) Gender
Rationale: Nominal data represents categories without a specific order, such as
gender.
Question 8
What is the variance of the following data set?
5, 7, 3, 9
• A) 4
• B) 5
• C) 6
• D) 2
Correct Option: A) 4
Rationale: Variance is calculated by finding the mean, subtracting each value from the
mean, squaring the results, and averaging those squared differences.
Question 9
If the p-value is less than the significance level (α), what should you do?
• A) Fail to reject the null hypothesis
• B) Accept the null hypothesis
• C) Reject the null hypothesis
• D) Collect more data
