Fall Semester 2025 UNISA Assignment: QMI1500 Elementary Quantitative
Methods – Complete Solved Assignment with Step-by-Step Answers and
Exam-Focused Study Guide (Updated 2025 Edition)
Question 1:
What is the mean of the following set of numbers? 5, 10, 15, 20.
• A) 10
• B) 15
• C) 12.5
• D) 20
CORRECT ANSWER: C) 12.5
Rationale: The mean is calculated by adding all the numbers (5 + 10 + 15 + 20 = 50) and
dividing by the count of numbers (4). So, 50/4 = 12.5.
Question 2:
Which of the following measures of central tendency is affected by extreme
values?
• A) Mode
• B) Mean
• C) Median
• D) None of the above
CORRECT ANSWER: B) Mean
Rationale: The mean can be significantly influenced by outliers or extreme values,
whereas the mode and median remain unaffected by such values.
Question 3:
What is the standard deviation used to measure?
• A) Central tendency
• B) Variability
• C) Frequency
• D) Rate of change
CORRECT ANSWER: B) Variability
Rationale: Standard deviation quantifies the amount of variation or dispersion in a set
of values, indicating how much individual data points differ from the mean.
,Question 4:
If a set of data is normally distributed, what percentage of values lies within one
standard deviation of the mean?
• A) 50%
• B) 68%
• C) 95%
• D) 99%
CORRECT ANSWER: B) 68%
Rationale: In a normal distribution, approximately 68% of the data falls within one
standard deviation of the mean.
Question 5:
Which of the following describes a correlation coefficient of -1?
• A) Strong positive correlation
• B) Strong negative correlation
• C) No correlation
• D) Weak positive correlation
CORRECT ANSWER: B) Strong negative correlation
Rationale: A correlation coefficient of -1 indicates a perfect inverse relationship
between two variables, meaning as one increases, the other decreases.
Question 6:
Which of the following distributions is symmetric?
• A) Normal distribution
• B) Uniform distribution
• C) Exponential distribution
• D) Poisson distribution
CORRECT ANSWER: B) Uniform distribution
Rationale: A uniform distribution is symmetric because all outcomes have an equal
probability. In contrast, normal distributions are symmetric, while exponential and
Poisson distributions are typically skewed.
Question 7:
In hypothesis testing, what is the null hypothesis (H0)?
, • A) The hypothesis that an effect exists
• B) The hypothesis that no effect or difference exists
• C) The alternative hypothesis
• D) The hypothesis stating all outcomes are equal
CORRECT ANSWER: B) The hypothesis that no effect or difference exists
Rationale: The null hypothesis (H0) states that there is no significant effect or
difference between groups, serving as a baseline against which the alternative
hypothesis (H1) is tested.
Question 8:
What does a p-value of 0.05 signify in hypothesis testing?
• A) Strong evidence against the null hypothesis
• B) Evidence in favor of the null hypothesis
• C) A significance level indicating a 5% risk of concluding that a difference
exists when there is none
• D) No evidence at all
CORRECT ANSWER: C) A significance level indicating a 5% risk of concluding that a
difference exists when there is none
Rationale: A p-value of 0.05 suggests that there is a 5% chance of rejecting the null
hypothesis when it is actually true, commonly used as a threshold for determining
statistical significance.
Question 9:
What is the primary purpose of regression analysis?
• A) To calculate mean values
• B) To find the mode of a dataset
• C) To predict the value of a dependent variable based on one or more
independent variables
• D) To determine the population size
CORRECT ANSWER: C) To predict the value of a dependent variable based on one or
more independent variables
Rationale: Regression analysis helps model and analyze relationships between
variables, allowing for predictions of the dependent variable based on changes in
independent variables.
Methods – Complete Solved Assignment with Step-by-Step Answers and
Exam-Focused Study Guide (Updated 2025 Edition)
Question 1:
What is the mean of the following set of numbers? 5, 10, 15, 20.
• A) 10
• B) 15
• C) 12.5
• D) 20
CORRECT ANSWER: C) 12.5
Rationale: The mean is calculated by adding all the numbers (5 + 10 + 15 + 20 = 50) and
dividing by the count of numbers (4). So, 50/4 = 12.5.
Question 2:
Which of the following measures of central tendency is affected by extreme
values?
• A) Mode
• B) Mean
• C) Median
• D) None of the above
CORRECT ANSWER: B) Mean
Rationale: The mean can be significantly influenced by outliers or extreme values,
whereas the mode and median remain unaffected by such values.
Question 3:
What is the standard deviation used to measure?
• A) Central tendency
• B) Variability
• C) Frequency
• D) Rate of change
CORRECT ANSWER: B) Variability
Rationale: Standard deviation quantifies the amount of variation or dispersion in a set
of values, indicating how much individual data points differ from the mean.
,Question 4:
If a set of data is normally distributed, what percentage of values lies within one
standard deviation of the mean?
• A) 50%
• B) 68%
• C) 95%
• D) 99%
CORRECT ANSWER: B) 68%
Rationale: In a normal distribution, approximately 68% of the data falls within one
standard deviation of the mean.
Question 5:
Which of the following describes a correlation coefficient of -1?
• A) Strong positive correlation
• B) Strong negative correlation
• C) No correlation
• D) Weak positive correlation
CORRECT ANSWER: B) Strong negative correlation
Rationale: A correlation coefficient of -1 indicates a perfect inverse relationship
between two variables, meaning as one increases, the other decreases.
Question 6:
Which of the following distributions is symmetric?
• A) Normal distribution
• B) Uniform distribution
• C) Exponential distribution
• D) Poisson distribution
CORRECT ANSWER: B) Uniform distribution
Rationale: A uniform distribution is symmetric because all outcomes have an equal
probability. In contrast, normal distributions are symmetric, while exponential and
Poisson distributions are typically skewed.
Question 7:
In hypothesis testing, what is the null hypothesis (H0)?
, • A) The hypothesis that an effect exists
• B) The hypothesis that no effect or difference exists
• C) The alternative hypothesis
• D) The hypothesis stating all outcomes are equal
CORRECT ANSWER: B) The hypothesis that no effect or difference exists
Rationale: The null hypothesis (H0) states that there is no significant effect or
difference between groups, serving as a baseline against which the alternative
hypothesis (H1) is tested.
Question 8:
What does a p-value of 0.05 signify in hypothesis testing?
• A) Strong evidence against the null hypothesis
• B) Evidence in favor of the null hypothesis
• C) A significance level indicating a 5% risk of concluding that a difference
exists when there is none
• D) No evidence at all
CORRECT ANSWER: C) A significance level indicating a 5% risk of concluding that a
difference exists when there is none
Rationale: A p-value of 0.05 suggests that there is a 5% chance of rejecting the null
hypothesis when it is actually true, commonly used as a threshold for determining
statistical significance.
Question 9:
What is the primary purpose of regression analysis?
• A) To calculate mean values
• B) To find the mode of a dataset
• C) To predict the value of a dependent variable based on one or more
independent variables
• D) To determine the population size
CORRECT ANSWER: C) To predict the value of a dependent variable based on one or
more independent variables
Rationale: Regression analysis helps model and analyze relationships between
variables, allowing for predictions of the dependent variable based on changes in
independent variables.
