Question

A survey of 525 people was conducted to determine whether they have brothers and sisters.

• The results showed that 24% of the people surveyed do not have a sister and 68% of the people surveyed have a
brother
The results also show that 93 of the people surveyed do not have sister and do not have a brother.
Complete the two-way frequency table to show the results of the survey.
Have a Brother
Do Not Have a Brother
Total
Have
Sister
Do
Not
Have
а
Sister
Total
525

Answer 1

Have a brother Do not have a brother Total

Have a sister 324 75 399

Do not have a sister 33 93 126

Total 357 168 525

Step-by-step explanation:

1. Build the structure of the two-way table:

Have a brother Do not have a brother Total

Have a sister

Do not have a sister

Total

2. Fill in the given information

• 525 people surveyed: that is the total of the columns and of the rows:

Have a brother Do not have a brother Total

Have a sister

Do not have a sister

Total 525

• 24% of the people surveyed do not have a sister

24% × 525 = 126

That is the total of the row Do not have a sister

Have a brother Do not have a brother Total

Have a sister

Do not have a sister 126

Total 525

• and 68% of the people surveyed have a brother

68% × 525 = 357

That is the total of the column have a brother

Have a brother Do not have a brother Total

Have a sister

Do not have a sister 126

Total 357 525

• 93 of the people surveyed do not have sister and do not have a brother.

That is the intersection of the row do not have a sister and the colum do not have a brother

Have a brother Do not have a brother Total

Have a sister

Do not have a sister 93 126

Total 357 525

The other missing cells can be found by difference:

• 126 - 93 = 33

• 525 - 357 = 168

Have a brother Do not have a brother Total

Have a sister

Do not have a sister 33 93 126

Total 357 168 525

• 357 - 33 = 324

• 168 - 93 = 75

• 525 - 126 = 399

Have a brother Do not have a brother Total

Have a sister 324 75 399

Do not have a sister 33 93 126

Total 357 168 525

Done!