## STATISTICS

Is the study or the methods of collecting, summarizing and presenting data and interpreting the information.
MEASURES OF CENTRAL TENDENCY
1. Mean
2. Median
3. Mode

MEAN “X”
Is obtained by adding up all the data values then divide by the number of characters.
I.e.
i.e. =mean
x1+x2+x3………. Sum of observations
N =number of observation

Example
1. Find mean score from the following scores of biology test 10, 25, 45, 15,63 42,7
=
= 29.57

When the data is given with frequency or in grouped data;
= or
f= frequency
∑= summation

2. Find the mean number of children per family from the following table
 No. of children [x] 0 1 2 3 4 5 6 7 8 No. of families [f] 3 6 7 8 10 12 8 4 2

Solution

Finding the mean of the numbers in the table below;
 No. of children [x] No. of families [f] fx 0 3 0 1 6 6 2 7 14 3 8 24 4 10 40 5 12 60 6 8 48 7 4 28 8 2 16 Total 60 236

= =

= 3.93

Exercise
 Class interval Class mark [x] Frequency [f] fx 91-95 93 0 0 86-90 88 1 88 81-85 83 6 498 76-80 78 10 780 71-75 73 15 1095 66-70 68 34 2312 61-65 63 22 1386 56-60 58 10 580 51-55 53 2 106 N=100 ∑fx=6845
 Class interval Class mark[x] F D=x-A fd 91-95 93 0 35 0 86-90 88 1 30 30 81-85 83 6 25 150 76-80 78 10 20 200 71-75 73 15 15 225 66-70 68 34 10 340 61-65 63 22 5 110 56-60 58 10 0 0 51-55 53 2 -5 -10 Total 100 1045
 Class mark[x] f fx 61 10 610 64 20 1280 67 30 2010 70 15 1050 73 5 365 Total 80 5315
 Class mark frequency 41-46 3 35-40 4 29-34 9 23-28 12 17-22 18 11-16 28 5-10 26
 Class mark[x] Frequency [f] D= x-A fd 41-46 3 30 90 35-40 4 24 96 29-34 9 18 162 23-28 12 12 144 17-22 18 6 108 11-16 28 0 0 5-10 26 -6 -156 Total 100 444
 Number of visits frequency 5 16 6 33 1 47 8 54 9 31 10 10 11 4 12 2 13 0 14 2 15 1
 Number of visits[x] Frequency [f] Fx 5 16 80 6 33 198 7 47 329 8 54 432 9 31 279 10 10 100 11 4 44 12 2 24 13 0 0 14 2 28 15 1 15 Total 200 1529

 Length [mm] f Cumulative frequency 88-96 3 3 97-105 5 8 106-114 9 17 115-123 12 29 124-132 5 34 133-141 4 38 142-150 2 40 Total 40 169
 Marks frequency Cumulative frequency 11-20 1 1 21-30 3 4 31-40 10 14 41-50 21 35 51-60 6 41 61-70 5 46 71-80 4 50 50

 Class mark frequency Cumulative frequency 92 3 3 101 5 18 119 10 33 128 13 46 137 7 53 Total 53
 Class mark frequency Cumulative frequency 15 0 0 20 5 5 25 15 20 30 12 32 35 10 42 40 0 42
 Height [cm] 160 165 170 175 180 185 frequency 2 12 32 24 21 8
 Height in [cm] frequency Cumulative frequency ecolebooks.com 160 3 3 165 12 15 170 32 47 175 24 71 180 21 92 185 8 100 total 100
 Class mark frequency Cumulative frequency 15.5 1 1 25.5 3 4 35.5 10 14 45.5 21 35 55.5 6 41 65.5 5 46 75.5 4 50 Total 50
 Wages in [TSHS} frequency Cumulative frequency 55 8 8 65 10 18 75 16 34 85 15 49 95 10 59 105 5 64 Total 64
 Mass in kg frequency Cumulative frequency 47 0 47 0 0 52 16 16 51 20 36 62 14 50 61 12 62 72 8 70 77 6 76 82 4 80 87 0 80 Total 80
 Height in cm frequency 82 10 85 11 88 14 91 10 94 9 97 6 Total 60

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I will like to know more about math

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