Deck 3: Data and Their Accuracy

Question 1

As a researcher conducting work at a local visitor attraction you count the number of visitors every day for a week, recording gender and the number of adult and child tickets sold. How might this data be classified?

A) Primary, discrete data
B) Primary, continuous data
C) Secondary, discrete data
D) Secondary, continuous data

Answer 1

Primary, discrete data

Question 2

What term is used when numbers are rounded in one direction only (e.g. ages are usually only rounded down)?

A) Biased rounding
B) Rounding Down
C) Uni-directional rounding
D) Fair rounding

Answer 2

Biased rounding

Question 3

An insurance company reports the average number of transactions each day as 1,850 (n10). What is the correct range of possible true values?

A) [1,849, 1,851]
B) [1,845, 1,855]
C) [1,800, 1,900]
D) [1,750, 1,950]

Answer 3

[1,845, 1,855]

Question 4

A ball-bearing factory makes 4,000,000 ±5% ball bearings each day. Which option below represents the minimum and maximum number of ball bearings actually produced each day?

A) [3,600,000, 4,400,000]
B) [3,900,000, 4,100,000]
C) [3,800,000, 4,200,000]
D) [3,500,000, 4,500,000]

Question 5

Which answer below IS an example of planned or predictable error?

A) Incomplete records
B) Rounding of discrete data
C) Data collected from a sample
D) Over-complicated or poor survey questions

Question 6

Why is it usually considered preferable to use numbers subject to compensating errors rather than numbers subject to systematic errors?

A) Compensating errors tend to cancel out when they are combined
B) Systematic errors are caused by errors in data collection
C) Compensating errors are more likely to be close to the true value
D) Systematic errors are inappropriate in a research setting

Question 7

You have been asked to estimate the number of books in school libraries in Izmir, Turkey. You know there exactly 85 schools and that on average each library has 12,500 (n100) books. What is the correct range of values?

A) [1,054,000, 1,071,000]
B) [1,020,000, 1,105,000]
C) [1,062,075, 1,062,925]
D) [1,058,250, 1,066,750]

Question 8

The average cost of a week-long holiday for 2 adults and 2 children is reported as being AED 10,200 (Emirati Dirham). You know the actual value was calculated as AED 10,197.89 but that it has been rounded. What is this process called?

A) Biased rounding
B) Over rounding
C) Fair rounding
D) Discrete rounding

Question 9

A colleague tells you that the average price of Zinc has increased by 33% in 3 years. In the same period, the price of Copper has increased by 25% Which of the following statements IS true?

A) The price of Zinc has increased every year
B) The price of Zinc is higher than the price of Copper
C) The absolute increase in the price of Zinc is greater than the absolute increase in the price of Copper
D) The percentage increase in the price of Zinc is greater than the percentage increase in the price of Copper

Question 10

A farmer records wheat production as being 2.5 tons per hectare. Which is NOT a potential source of error in this calculation?

A) Mistakes in how the figures are recorded
B) Difficulties in accurately recording continuous data
C) Only recording information from two-thirds of his fields
D) Variation between yields on each field