Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Data Collection: The process of gathering information by observing, asking questions, or measuring.
Tally Marks: A quick way of recording data. We use vertical lines (|) for each count and a diagonal line across four lines to represent five (||||).
Frequency: The total number of times a particular value or item appears in a data set.
Frequency Table: A table that organizes data into categories, showing the tally marks and the final numerical count (frequency) for each.
Interpreting Data: Using the table to find the most common (mode), least common, or the total number of items collected.
📐Formulae
Tally for 5 = ||||
Total Frequency = (The sum of all individual category totals)
💡Examples
Problem 1:
A teacher recorded the favorite colors of 15 students: Blue, Red, Blue, Green, Blue, Red, Green, Blue, Blue, Red, Green, Blue, Red, Blue, Green. Create a frequency table.
Solution:
Color | Tally | Frequency Blue | |||| || | 7 Red | |||| | 4 Green | |||| | 4
Explanation:
Count each color one by one. For Blue, we count 7 occurrences, so we draw a bundle of 5 and 2 extra marks. For Red and Green, we count 4 each. The sum of frequencies (7+4+4) equals the total 15 students.
Problem 2:
Look at a frequency table where 'Apples' has a frequency of 12. How would this be represented in the Tally column?
Solution:
|||| |||| ||
Explanation:
To represent 12 using tally marks, we group them into fives. Two groups of five (5 + 5 = 10) plus two individual marks (10 + 2 = 12).
Problem 3:
In a survey about pets, the frequencies recorded were: Dogs (8), Cats (5), and Hamsters (3). What is the total number of people surveyed?
Solution:
16 people
Explanation:
To find the total number of people, you add the frequencies of all categories together: .