The company doesn’t have any employees below 20 years of age. Anyone who has not yet passed his 30th birthday belongs to the 20-30 group. Anyone who has passed their 30th birthday, even by one day, but has not yet reached the age of 40, belongs to the 30-40 group. Anyone whose 30th, 40th, 50th, or 60th birthday falls exactly on the day that they fill out the questionnaire is told to consider themselves in the younger age group.

For example, an employee who turned 30 on the day she completed the questionnaire would be included in the 20-30 group, and not the 30-40 group.

The student randomly compiles the answers to the questionnaires in the following table:

Each row in the table is called an observation. A collection of observations comprises a sample. This table represents the sample. In this case, the sample includes 30 observations. The information found in the sample is very specific and includes very specific details. When the student wishes to investigate, for example, only the gender of employees, they will prefer to arrange a new, shorter, and more informative table, as we will soon see.

The Crude Data

Gender

Family Status

No. of Children

Status in the Company

Age

Male

Single

0

Junior

20-30

Female

Single

0

Intermediate

20-30

Male

Married

2

Senior

40-50

Female

Divorced

2

Intermediate

30-40

Male

Married

2

Junior

30-40

Female

Married

1

Junior

20-30

Female

Married

3

Junior

40-50

Male

Married

3

Intermediate

40-50

Male

Divorced

3

Senior

50-60

Female

Married

4

Senior

40-50

Female

Widow

2

Senior

50-60

Male

Single

0

Junior

20-30

Female

Divorced

1

Junior

30-40

Female

Married

1

Intermediate

30-40

Female

Married

2

Intermediate

30-40

Male

Married

2

Intermediate

40-50

Female

Married

3

Junior

40-50

Female

Married

3

Junior

50-60

Male

Married

3

Junior

50-60

Female

Single

0

Junior

30-40

Female

Married

1

Junior

30-40

Female

Married

2

Junior

40-50

Female

Married

2

Senior

50-60

Female

Divorced

2

Junior

40-50

Female

Single

0

Intermediate

20-30

Female

Married

1

Junior

30-40

Female

Married

2

Junior

40-50

Female

Married

3

Intermediate

50-60

Female

Single

0

Junior

40-50

Female

Married

4

Junior

50-60