Tutorial 1 – Chapter 1 questions
Section A
For each variable in Questions 1 to 8, identify whether they are
(i)
(ii)
Continuous or discrete
Qualitative or quantitative
AND give their level of measurement.
Q1: The flavours of instant cappuccinos sold at supermarkets.
Q2: The number of cappuccinos sold at a family restaurant.
Q3: The weight of the coffee beans used monthly at a coffee shop.
Q4: The “Best by” dates on packets of coffee beans.
Q5: The temperature of “cold chocolate” drinks.
Q6: The service rating – excellent, good, average, poor – at a restaurant.
Q7: The level of study of university students (1st year, 2nd year etc) that drink coffee daily.
Q8: The number of years spent studying at university.
Section B
Consider the situations described in Questions 9 and 10. Identify which numerical values
(numbers) are samples, populations, statistics and parameters.
Q9: There are 800 runners registered to run in a marathon. It is known that the average age
of the 800 runners is 41 years. At a water station 55 runners were asked their age. Their
average age was found to be 36.5 years.
Q10: The Department of Education was concerned about the schooling in high schools in a
particular area. Three hundred (300) students from these high schools were randomly
chosen to write a standardized test. Their average test mark of 61% was quite similar
to the national average test mark of 65%.
Q11: What sampling method is being used in Question 9?
Section C
Consider each of the studies described in Questions 12 to 15. Identify which are
observational and which are designed.
Q12: In a study, a group of adults was randomly divided into two groups. One group was
told to drink 5 cups of coffee (but no tea) each day for a week, while the other group
was told to drink 5 cups of tea (but no coffee) each day for a week. Researchers then
compared how long it took individuals in each group to fall asleep.
Q13: In a study, the social media habits of 200 teenagers was examined. Each teenager was
classified as either a light, a moderate or a heavy social media user. The researchers
looked at which groups tended to be happier.
Q14: A study randomly assigned teenagers to one of two groups:
• One group was directed to use social media sites as they usually do.
• One group was blocked from social media sites.
The researchers looked at which group tended to be happier.
Q15: In a study, a random sample of adults were asked about their sleeping and coffee
drinking habits. The data showed that people who drank more than 5 cups of coffee a
day were more likely to go to sleep later than those that drank at most 5 cups of
coffee a day.
Section D
Consider the statements in Questions 16 to 20. Identify which are true and which are false.
Q16: The sample frame is the same as the population.
Q17: The statistics calculated from biased samples might not be good approximations of the
population parameters.
Q18: Quota sampling is not an example of probability sampling.
Q19: A census is a study done on a biased sample.
Q20: Qualitative variables can be continuous variables.
Section E
Cadbury wants to market a new type of chocolate and needs to know how potential
customers might react to the product. Quota sampling is to be used to select a sample for a
reaction survey. It is decided that age (under 21, 21 to 40, over 40), gender and income class
(low, middle, high) are characteristics that might affect the customers’ opinions.
Q21: How many groups/categories will be used?
Q22: If 15 people are selected for each of the groups/categories, how large a sample will be
selected?
Question 23
Many “Home Chefs” apply to take part in a cooking competition. On the application form
the Home Chefs are asked if they have a full time job, a part time job, or no job. Of the 760
applicants, 228 have full time jobs, 405 have part time jobs and the rest have no job. The
organisers want to take a stratified sample of 50 applicants. They want the sample
proportion of applicants in each job category to reflect that of all the applicants.
Approximately how many applicants should be chosen from each of the job categories?
Question 24
Suppose a systematic sample of 25 items is to be selected from a population of 500 items.
The items in the population are numbered 1 to 500 (Item 1 to Item 500). If the 124th item
(Item 124) is randomly selected as the first item of the sample, what is the number of the 5th
item selected into the sample?
There will also be a few questions based on Chapter 1 Excel