The table provides on road accidents reported to the police for the days in December Accidents reported Frequency
0-5 9
6-10 10
11-15 6
16-20 6

Estimate the mean.
Give your answer rounded to 1 DP.

Step-by-step explanation:

Given

Let accidents reported be represented by x and the frequency be represented by f

x -----   f

0-5 --   9

6-10 --  10

11-15 --   6

16-20 -- 6

Required

Calculate the Mean;

To calculate the mean of a grouped data, the first step is to calculate the midpoint of the observation;

When x = 0 - 5

Midpoint = 0.5(0 + 5) = 0.5 * 5 = 2.5

When x = 6 - 10

Midpoint = 0.5(6 + 10) = 0.5 * 16 = 8

When x = 11 - 15

Midpoint = 0.5(11 + 15) = 0.5 * 26 = 13

When x = 16 - 20

Midpoint = 0.5(16 + 20) = 0.5 * 36 = 18.

So, the new table is as follows;

x ------- f

2.5 ----  9

8 -----  10

13 ------ 6

18 ------ 6

Mean is calculated by ∑fx/∑f

Where ∑fx represent sum of the product of f and x

∑f represent sum of frequency

∑fx = 2.5 * 9 + 8 * 10 + 13 * 6 + 18 * 6

∑fx = 288.5

∑f = 9 + 10 + 6 + 6

∑f = 31

So,

Hence, the mean of road accidents in December is 9.3

step-by-step explanation:

the ratio of white tiles to blue tiles is 48: 16. the ratio in it's simplest form is 3: 1.

step-by-step explanation:

ratio: take the first number and add a colon next to it, then add the second number after that. make sure the ratio order matches up with the written problem!

simplest form: we can simplify the ratio 48 : 16 by dividing both terms by the greatest common factor (gcf).

the gcf of 48 and 16 is 16.

divide both terms by 16:

48 ÷ 16 = 3

16 ÷ 16 = 1

reducing to simplest form:

48 : 16 = 3 : 1