Page 40 - Basic Statistics

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c. Variance:

To calculate the variance, first performed the following preliminary

count:

X = 18 + 3 + . . . + 62 = ……..
 i

 X = 18 + 3 + …. + 62 = ……
2
2
2
2
i

2
 n 
  X 
n  i 
 X 2 −  i= 1 
i
variance S = i= 1 n
2
n 1 -
..........− ((........ ) 2 / 12 )
=
12 − 1

= ……….

d. Standard deviation :

The standard deviation is the square root of the variance. If you have
2
obtained variance S = …….. then the standard deviation is

...
S = .......... = …….

Problem 2.4:

Data on 100 student high recorded in Table 2.4. Sort observations from

the lowest to the highest observation. Do Tolly to complement the contents of
Table 2.5. Furthermore calculate:

a. Range

b. Interquartile range

c. Variance

d. Standard deviation

~~* CHAPTER 2 NUMERICAL MEASURES TO SUMMARIZE DATA *~~