Unit 4 Quiz: Statistics and Probability
Comprehensive assessment covering all 20 lessons: data types, sampling, displays, measures of centre and spread, bivariate data, and probability.
Multiple Choice
Select the best answer for each question. Each question is worth 1 mark.
1 mark Which of the following is continuous numerical data?
1 mark The median of 5, 7, 8, 10, 12, 15, 20 is:
1 mark For the data 2, 3, 3, 5, 7, 100, the most appropriate measure of centre is:
1 mark A box plot displays:
1 mark The interquartile range represents:
1 mark On a scatter plot, a strong positive correlation means:
1 mark Extrapolation is less reliable than interpolation because:
1 mark A fair coin is tossed twice. The probability of getting at least one head is:
1 mark Events A and B are mutually exclusive. P(A) = 0.3, P(B) = 0.4. P(A or B) =
1 mark P(A|B) = P(A) when:
1 mark In a two-way table, row totals show:
1 mark The mean of 4, 6, 8, x, 12 is 8. The value of x is:
1 mark A histogram with classes 10-19, 20-29, 30-39 has class width:
1 mark The only measure of spread that uses all data values is:
1 mark Correlation between ice cream sales and drowning incidents is likely due to:
Short Answer
Show all working and justify your answers.
Question 16
The test scores of 10 students are: 45, 52, 58, 62, 68, 72, 75, 80, 85, 92
(a) Calculate the mean and median. (2 marks)
(b) Calculate the range and interquartile range. (2 marks)
(c) Identify any outliers using the 1.5 × IQR rule. (1 mark)
Question 17
A survey of 120 students recorded whether they play sport and whether they play a musical instrument.
Sport only: 45, Instrument only: 30, Both: 25, Neither: 20
(a) Complete a two-way table for this data. (2 marks)
(b) Calculate the probability that a randomly chosen student plays sport. (1 mark)
(c) Given that a student plays an instrument, what is the probability they also play sport? (2 marks)
Question 18
Two classes sat the same test. Class A: mean = 72, standard deviation = 5. Class B: mean = 68, standard deviation = 12.
(a) Compare the performance of the two classes using the mean and standard deviation. (2 marks)
(b) A student in Class A scored 82. A student in Class B also scored 82. Explain which student performed better relative to their class. (3 marks)