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# Averages

Averages. www.mathsguru.co.uk. BASIC AVERAGES. Example. Twelve people sat a maths test. Their marks out of 10 are recorded below. . 1 1 9 8 7 6 8 6 10 2 8 6. the most common value(s). The MODE is ……………….……………….

## Averages

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1. Averages www.mathsguru.co.uk

2. BASIC AVERAGES Example. Twelve people sat a maths test. Their marks out of 10 are recorded below. 1 1 9 8 7 6 8 6 10 2 8 6 the most common value(s). The MODE is ……………….……………… The mode of the above data are 6 and 8 marks.

3. BASIC AVERAGES Example. Twelve people sat a maths test. Their marks out of 10 are recorded below. 1 1 9 8 7 6 8 6 10 2 8 6 the “middle” value. The MEDIAN is …………….……………………. ………………………………….. Place the values in order first! 1 1 2 6 6 6 7 8 8 8 9 10 The median of the above data is 6.5 marks.

4. BASIC AVERAGES Example. Twelve people sat a maths test. Their marks out of 10 are recorded below. 1 1 9 8 7 6 8 6 10 2 8 6 The MEAN is the only average which uses ALL the data. add up all the values and then divide by the number of items. To calculate the mean we …………………………………… …………………………………... The total marks = 1 + 1 + 9 + 8 + 7 + 6 + 8 + 6 + 10 + 2 + 8 + 6 = 72 The mean of the above data = 72 12 which equals 6 marks.

5. EXERCISE For the following sets of data, find the mode, the median and the mean. i) 2 4 6 6 7 11 13 ii) 1 8 3 12 8 4 15 5 iii) 7 5 21 8 6 7 20 6 iv) 4 8 12 3 3 6 v) 4 5 9 5 6 4 2

6. ANSWERS TO EXERCISE i) 2 4 6 6 7 11 13 ii) 1 8 3 12 8 4 15 5 iii) 7 5 21 8 6 7 20 6 iv) 4 8 12 3 3 6 v) 4 5 9 5 6 4 2

7. FREQUENCY TABLES The following frequency table shows the weights of the apples sold in a shop: 8 apples weighed 30 grams each etc. There are 8 + 12 + 6 + 4 = 30 apples The modal (most common) weight is 40 grams.

8. 30 30 30 30 30 30 30 40 40 40 40 40 30 40 40 FREQUENCY TABLES The following frequency table shows the weights of the apples sold in a shop: There are 8 + 12 + 6 + 4 = 30 apples The median weight is the weight of the 15th apple (the middle one!) The median weight is 40 grams.

9. FREQUENCY TABLES The following frequency table shows the weights of the apples sold in a shop: There are 8 + 12 + 6 + 4 = 30 apples The mean is the total combined weight of all the apples divided by the number of apples. Total weight = 8  30 + 12  40 + 6  50 + 4  60 = 1260 grams. The mean weight is 1260  30 = 42 grams.

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