A factory’s quality control department has tested every 50th item produced for possible defects.
What type of sampling has been used?
A. Random
B. Stratified
C. Systematic
D. Numerical
Statistics, STD2 S1 2006 HSC 23c
Vicki wants to investigate the number of hours spent on homework by students at her high school.
- Briefly describe a valid method of randomly selecting 200 students for a sample. (1 mark)
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- Vicki chooses her sample and asks each student how many hours (to the nearest hour) they usually spend on homework during one week.
The responses are shown in the frequency table.
What is the mean amount of time spent on homework? (2 marks)
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Show Worked Solution
i.
MARKER’S COMMENT: This “routine” exercise of finding a mean from grouped data was incorrectly answered by most students! The best responses copied the table and inserted a class-centre column (see solution).
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Statistics, STD2 S1 2007 HSC 17 MC
Ms Wigginson decided to survey a sample of 10% of the students at her school.
The school enrolment is shown in the table.
She surveyed the same number of students in each year group.
How would the numbers of students surveyed in Year 10 and Year 11 have changed if Ms Wigginson had chosen to use a stratified sample based on year groups?
- Increased in both Year 10 and Year 11
- Decreased in both Year 10 and Year 11
- Increased in Year 10 and decreased in Year 11
- Decreased in Year 10 and increased in Year 11
Statistics, STD2 S1 2011 HSC 25a
A study on the mobile phone usage of NSW high school students is to be conducted.
Data is to be gathered using a questionnaire.
The questionnaire begins with the three questions shown.
- Classify the type of data that will be collected in Q2 of the questionnaire. (1 mark)
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- Write a suitable question for this questionnaire that would provide discrete ordinal data. (1 mark)
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- An initial study is to be conducted using a stratified sample.
Describe a method that could be used to obtain a representative stratified sample. (1 mark)
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- Who should be surveyed if it is decided to use a census for the study? (1 mark)
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Statistics, STD2 S1 2012 HSC 2 MC
Handmade chocolates are checked for size and shape. Every 30th chocolate is sampled.
Which term best describes this type of sampling?
- Census
- Random
- Stratified
- Systematic
Statistics, STD2 S1 2013 HSC 8 MC
A high school has 100 students in each year group, Year 7 to Year 12. A survey is to be conducted to determine the average number of text messages sent per month by students at the school.
Which of the following would provide the most representative sample for this survey?
- All Year 7 students
- All physics students in Year 11 and 12
- 20 students chosen at random from each year group
- 120 students chosen at random from the school roll