Using two way tables to find
probabilities
By William Gibbs
This table show some information
on how staff got to school.
NONE OF THEM CAME BY CAR
Walk Bus Cycle
Total
Monday
4
p
3
12
Tuesday
7
Q
U
T
Wednesday r
9
s
25
Fill in the missing numbers
Walk Bus Cycle
Total
Mon
4
p
3
12
Tues
7
I
H
S
Total T
9
s
25
This is how many walked
Walk
4
7
T
We Need to
Find “T”
This is how many walked
2 + 7 = 11
Walk
We Add these
4
7
So
this is
11
T
This is how many walked
2 + 7 = 11
Walk
We Add these
4
7
So
this is
11
11
So now we know that T is 11
Walk Bus Cycle
Total
Mon
4
p
3
12
Tues
7
I
H
S
9
s
25
Total 11
Now to do it cross ways
Mon
So we add
4+P+3=12
4
p
3
So 4+3-12=5
12
Now to do it cross ways
Mon
So we add
4+P+3=12
4
5
3
So 4+3-12=5
12
So now we know that P is 5
Walk Bus Cycle
Total
Mon
4
5
3
12
Tues
7
I
H
S
9
s
25
Total 11
Now lets do the rest
Walk Bus Cycle
Total
Mon
4
5
3
12
Tues
7
I
H
S
9
s
25
Total 11
Now lets do the rest
Walk Bus Cycle
Total
Mon
4
5
3
12
Tues
7
4
H
S
9
s
25
Total 11
Now lets do the rest
Walk Bus Cycle
Total
Mon
4
5
3
12
Tues
7
4
H
S
9
5
25
Total 11
Now lets do the rest
Walk Bus Cycle
Total
Mon
4
5
3
12
Tues
7
4
2
S
9
5
25
Total 11
Now lets do the rest
Walk Bus Cycle
Total
Mon
4
5
3
12
Tues
7
4
2
13
9
5
25
Total 11
The End
Now you should know how to use a
two way probability poster!