You ask 70 of your classmates if they have any siblings. complete the two-way frequency table to show the results of the survey.

The correct answer is: 125,75,200

• Two-way frequency chart

• Step 1:

Find b.
As, we know,
Totals appear at the end of each row and column

81 + b = 120

b = 120 – 81

b = 39

• Step 2:

Find d.
As, we know,
A sum of all counts (a grand total) is placed at the bottom right

120 + d = 200

d = 200 - 120

d = 80

• Step 3:

Find a.
As, we know,
Totals appear at the end of each row and column

a + 36 = d

a = 80 - 36

a = 44

• Step 4:

Find c
As, we know,
Totals appear at the end of each row and column

c + 75 = 200

c = 200 - 75

c = 125

• Final Answer:

	Boys	Girls	Total
Yes	81	44	125
No	39	36	75
Total	120	80	200