Data & Probability · Working with data · 2.2

Frequency tables.

A frequency table records how many times each category occurs. Reading it means pulling out counts and combining them — for example, adding all the frequencies to get the total number of data points.

01 / THE IDEA

See it work.

The data

See the values.

31522364

Watch the method

Frequency tables

Add the frequencies for the grand total.

1 / 2
A table shows counts 3, 5, 2, 6. What is the total?
1

Read each frequency

Each row’s count is in the table.

3,5,2,63 , 5 , 2 , 6
2

Total

Add the frequencies for the grand total.

3+5+2+6=163 + 5 + 2 + 6 = 16
02 / YOUR TURN

Practice until it feels automatic.

Your turn

Work it out.

Type the answer — a fraction or decimal is fine.

streak 0
best 0

…

— / WHY IT WORKS

The idea underneath.

Counts in rows

A frequency table organizes how often each value or category appears.

Why it works

Tally marks, tidied up.

03 / WORKED EXAMPLES

From easy to tricky.

EX 1easy

A table shows counts 4, 8, 4, 8. What is the total?

1

Read each frequency

Each row’s count is in the table. 4 , 8 , 4 , 8

2

Total

Add the frequencies for the grand total. 4 + 8 + 4 + 8 = 24

EX 2medium

A table shows counts 4, 3, 2, 3. What is the total?

1

Read each frequency

Each row’s count is in the table. 4 , 3 , 2 , 3

2

Total

Add the frequencies for the grand total. 4 + 3 + 2 + 3 = 12

EX 3hard

A table shows counts 3, 9, 1, 4. What is the total?

1

Read each frequency

Each row’s count is in the table. 3 , 9 , 1 , 4

2

Total

Add the frequencies for the grand total. 3 + 9 + 1 + 4 = 17

04 / COMMON TRAPS

Where students slip.

Trap

Adding the categories instead of the counts.

Fix

Sum the frequencies (the counts), not the labels.

Trap

Missing a row.

Fix

Include every row in the total.

05 / QUIZ

Test yourself.

The Test

12 problems across three tiers. Auto-graded on submit. Hints and a full walkthrough on every question. Your work is saved on this device — sign in to keep it across devices.

0/12Answered
How to answerType just the value. Formatting won't trip you up — we ignore spaces, capital letters, commas, and subscript style, so t₁ = 5, d = 3 and t1=5,d=3 both count. For a list of numbers, separate them with commas (e.g. 3, 10, 17).
Core

Core (4)

C1

A table shows counts 4, 7, 4, 9. What is the total?

Need a hint?
  • Read each frequency.
  • Add them all for the total.
C2

A table shows counts 9, 6, 6, 6. What is the total?

Need a hint?
  • Read each frequency.
  • Add them all for the total.
C3

A table shows counts 3, 3, 3, 7. What is the total?

Need a hint?
  • Read each frequency.
  • Add them all for the total.
C4

A table shows counts 2, 8, 7, 1. What is the total?

Need a hint?
  • Read each frequency.
  • Add them all for the total.
Apply

Apply (4)

A1

A table shows counts 6, 2, 6, 8. What is the total?

Need a hint?
  • Read each frequency.
  • Add them all for the total.
A2

A table shows counts 3, 4, 8, 8. What is the total?

Need a hint?
  • Read each frequency.
  • Add them all for the total.
A3

A table shows counts 4, 4, 7, 8. What is the total?

Need a hint?
  • Read each frequency.
  • Add them all for the total.
A4

A table shows counts 4, 8, 6, 9. What is the total?

Need a hint?
  • Read each frequency.
  • Add them all for the total.
Extension

Extension (4)

E1

A table shows counts 2, 9, 3, 1. What is the total?

Need a hint?
  • Read each frequency.
  • Add them all for the total.
E2

A table shows counts 8, 7, 9, 5. What is the total?

Need a hint?
  • Read each frequency.
  • Add them all for the total.
E3

A table shows counts 3, 9, 3, 8. What is the total?

Need a hint?
  • Read each frequency.
  • Add them all for the total.
E4

A table shows counts 5, 6, 2, 4. What is the total?

Need a hint?
  • Read each frequency.
  • Add them all for the total.