Checkpoint 1 of 3 10 MC + 2 Short Answer Covers Lessons 1-7

Checkpoint 1

Single Variable Data Analysis. Assess your understanding of data types, sampling, frequency tables, dot plots, stem-and-leaf plots, histograms, mean, median and mode.

Instructions: Complete all questions. For multiple choice, select one answer and click Check. For short answer, show all working. Your responses are saved automatically.

Section A - Multiple Choice

2 marks each. Select the best answer.

2 marks The height of students in a class measured in centimetres is:

Categorical data Discrete numerical data Continuous numerical data Qualitative data only

2 marks A researcher surveys only people leaving a shopping centre on a Saturday morning. This sampling method is:

Random sampling Stratified sampling Convenience sampling Systematic sampling

2 marks In a frequency table, the sum of all frequencies equals:

The number of different values The total number of data values The mean of the data The range of the data

2 marks The key advantage of a stem-and-leaf plot over a histogram is that it:

Is easier to draw Preserves the original data values Works for categorical data Shows the mean directly

2 marks A distribution with a long tail to the right is described as:

Symmetric Negatively skewed Positively skewed Bimodal

2 marks The mean of 4, 6, 8, 10, 12 is:

6 8 10 7.5

2 marks The median of 3, 5, 7, 9, 11, 13 is:

7 8 9 6.5

2 marks The mode of 2, 3, 3, 5, 5, 5, 7, 8 is:

2 3 5 8

2 marks For categorical data such as favourite sports, the only measure of centre that can be used is:

Mean Median Mode Range

2 marks If every value in a data set is increased by 3, the mean:

Stays the same Increases by 3 Decreases by 3 Triples

Section B - Short Answer

Show all working. 5 marks each.

Question 11

5 marks Apply / Analyse

A class of 20 students recorded the number of hours they spent on homework last week:

5, 6, 7, 7, 8, 8, 8, 9, 9, 10, 10, 10, 10, 11, 11, 12, 12, 13, 14, 15

(a) Calculate the mean. (1 mark)

(b) Find the median. (1 mark)

(d) A student claims the mean is the best measure of centre for this data. Do you agree? Justify your answer. (2 marks)

Question 12

5 marks Analyse / Evaluate

A researcher wants to find out how much time teenagers in Sydney spend on social media each day.

(a) Identify the population and suggest an appropriate sampling method. Explain why your method reduces bias. (2 marks)

(b) The researcher collects data from 50 teenagers and finds the mean is 3.2 hours with one outlier of 12 hours. Explain whether the mean or median would be more appropriate to report, and why. (3 marks)

I have completed Checkpoint 1 and checked my answers.