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

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

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!