Primary vs Secondary Data/Qualitative vs Quantitative/Population vs Sample
What type of data tells us about how something looks, feels, or smells (not numbers)?
Qualitative data
What does the word mean mean in math?
The average of a set of numbers
What does median mean in math?
The middle number in a set of numbers when they are put in order
What does mode mean in math?
The number that appears most often
If a student counts how many pets are in the class and records the numbers, is this qualitative or quantitative data?
Quantitative
Find the mean of these numbers:
2, 4, 6
4
Find the median of these numbers:
3, 1, 5
3
Find the mode of these numbers:
2, 4, 4, 6
4
The entire group you want to learn about in a survey is called the what?
Population
The total of 5 numbers is 50. What is the mean?
10
Find the median of these numbers:
2, 8, 4, 10, 6
6
Find the mode of these numbers:
1, 3, 3, 5, 7, 3
3
If you survey only 10 students out of the whole school to learn about favourite lunch foods, what is that group called?
Sample
Find the mean of these numbers:
8, 12, 10, 20
12.5
Find the median of these numbers:
1, 4, 7, 10
5.5
Find the mode of these numbers:
2, 5, 6, 5, 2, 5
5
A student uses results from a scientist’s climate report online for their project. Is this primary or secondary data — and why?
Secondary data — because the student did not collect the data themselves.
Three numbers have a mean of 10. Two of the numbers are 8 and 12. What is the third number?
10
(Mean 10 with 3 numbers → Total = 30
8 + 12 = 20 → 30 − 20 = 10)
Five numbers have a median of 8. Four of the numbers are 3, 6, 8, and 12. What could the fifth number be?
Any number that keeps 8 in the middle, such as 8, 9, or 10
This data set has no mode:
4, 7, 9, 12
Why does it have no mode?
Because no number appears more than once