Pass Check: Handling Data
Choose the right sampling method and check data collection is fair and unbiased.
Population
The whole group being studied.
Sample
A smaller part of the population chosen to represent the whole group.
Bias
When a sample or method unfairly favours certain outcomes, making results unreliable.
Stratified sample
A sample where each group is represented in proportion to its size in the population.
Quick check
Mixed quiz
1. A frequency table has values [10, 20, 30, 40, 50] with frequencies [9, 11, 4, 6, 2] respectively. Find the total frequency.
2. A survey of two shifts' productivity: Shift 1 median=40, IQR=10; Shift 2 median=45, IQR=25. Which shift is more consistent?
3. A frequency table has values [10, 20, 30, 40, 50] with frequencies [3, 5, 4, 6, 2] respectively. Find the total frequency.
4. A frequency table has values [10, 20, 30, 40, 50] with frequencies [5, 7, 4, 6, 4]. Estimate the mean of the data.
5. Two classes have these mean test scores: Class A mean=65, range=20; Class B mean=65, range=40. Which class has more consistent scores?
6. Two towns' average temperatures: Town A mean=18°C, range=6°C; Town B mean=18°C, range=15°C. Which town has more variable weather?
7. A frequency table has values [10, 20, 30, 40, 50] with frequencies [7, 9, 4, 6, 3] respectively. Find the total frequency.
8. A frequency table has values [10, 20, 30, 40, 50] with frequencies [7, 9, 4, 6, 3]. Estimate the mean of the data.