Data HandlingFrequency Tables

A frequency table is very simply a table showing the number of times something

happens.

Number of people in each car

1 2 3 4 5 6

Frequency 45 198 121 76 52 13

Data Handling

What we have to do with the information in this table is to work out the mode, median and the mean.

Number of people in each car

1 2 3 4 5 6

Frequency 45 198 121 76 52 13

Data Handling

Mode: This is the simplest to work out as we look for the highest frequency…There are 198 cars with two people in so the mode is 2.

NOT 198!

Number of people in each car

1 2 3 4 5 6

Frequency 45 198 121 76 52 13

Data Handling

Median: Where is the middle number? We first need to add up all the frequencies (505). Add 1 to make it an even number, 506

506 ÷ 2 = 253So the 253rd number is the median number

Number of people in each car

1 2 3 4 5 6

Frequency 45 198 121 76 52 13

Data Handling

Median: the first 45 cars had 1 personAdd to that 198 that had 2 people = 243The 253rd car will be one which has 3 people

Number of people in each car

1 2 3 4 5 6

Frequency 45 198 121 76 52 13

Data Handling

Mean: to work out the mean we need to do a more complicated bit of work.

We have to work out the total number of people all together and divide this by the total frequency. We need a new table.

Number of people in each car

1 2 3 4 5 6

Frequency 45 198 121 76 52 13

Data HandlingNumber of people in the car

Frequency Number in these cars

1 45 1 x 45 = 452 198 2 x 198 = 3963 121 3 x 121 = 3634 76 4 x 76 = 3045 52 5 x 52 = 2606 13 6 x 13 = 78

Totals 505 1446

The mean number of people in the car is

1446 ÷ 505 = 2.9