Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Primary Data: Data collected first-hand by the researcher (e.g., surveys, experiments).
Secondary Data: Data that has already been collected by someone else (e.g., internet, books, government records).
Qualitative Data: Descriptive data that cannot be measured with numbers (e.g., colors, names).
Quantitative Data: Numerical data that can be counted or measured.
Discrete Data: Quantitative data that can only take specific values, usually whole numbers (e.g., number of students).
Continuous Data: Quantitative data that can take any value within a range (e.g., height, weight, time).
Bias: A flaw in data collection that makes the results unrepresentative of the whole population (e.g., asking only your friends for their opinion).
Sample vs Population: A population is the entire group being studied; a sample is a smaller part of the population used for the study.
Tally Charts and Frequency Tables: Tools used to organize and count data systematically.
📐Formulae
💡Examples
Problem 1:
Classify the following types of data: (a) The number of goals scored in a match, (b) The time taken to run 100 meters, (c) The brand of shoes worn by students.
Solution:
(a) Quantitative - Discrete, (b) Quantitative - Continuous, (c) Qualitative.
Explanation:
Goals are counted in whole numbers (Discrete). Time is measured and can have infinite decimals (Continuous). Shoe brands are descriptive categories (Qualitative).
Problem 2:
A student wants to find out the most popular sport in a school of 1000 pupils. He asks 10 people in the football team. Explain why this sample is biased.
Solution:
The sample is biased because it is too small and not representative of the whole school.
Explanation:
By asking only members of the football team, the student is likely to get an over-representation of people who prefer football. A better method would be a random sample of students from different classes.
Problem 3:
In a survey of 40 people, 12 said their favorite fruit is Apple. Calculate the relative frequency of people who chose Apple.
Solution:
or .
Explanation:
Relative frequency is calculated by dividing the frequency of the specific event (12) by the total number of people surveyed (40).
Problem 4:
A researcher wants to know the average height of trees in a forest. Identify if this is Primary or Secondary data if the researcher goes into the forest to measure them himself.
Solution:
Primary Data.
Explanation:
Because the researcher is collecting the measurements first-hand specifically for his own study, it is classified as primary data.