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How do I find the standard deviation for these nine measurements?37.3055 g37.4005 g37.4673 g37.3520 g37.5109 g37.3970 g37.4819 g37.2700 g37.3763 g

1 Answer

4 votes

Measurements:

37.3055 g 37.4005 g 37.4673 g 37.3520 g 37.5109 g 37.3970 g 37.4819 g 37.2700 g 37.3763 g

a) The first step to find the standard deviation is to find the mean of these measurements. We have to add all the measurements and then divide them by 9.

mean = (37.3055 g + 37.4005 g + 37.4673 g + 37.3520 g + 37.5109 g + 37.3970 g + 37.4819 g + 37.2700 g + 37.3763 g) / 9

mean = 37.3957 g

b) Then for each number we substract the mean:

37.3055 g - 37.3957 g = - 0.0902

37.4005 g - 37.3957 g = 0.0048

37.4673 g - 37.3957 g = 0.0716

37.3520 g - 37.3957 g = -0.0437

37.5109 g - 37.3957 g = 0.1152

37.3970 g - 37.3957 g = 0.0013

37.4819 g- 37.3957 g = 0.0862

37.2700 g - 37.3957 g = -0.1257

37.3763 g - 37.3957 g = -0.0194

c) Now we have to square those results:

(0.0902 g)² = 0.00813604

(0.0048 g)² = 0.00002304

(0.0716 g)² = 0.00512656

(-0.0437 g)² = 0.00190969

(0.1152 g)² = 0.01327104

(0.0013 g)² = 0.00000169

(0.0862 g)² = 0.00743044

(-0.1257 g)² = 0.01580049

(-0.0194 g)² = 0.00037636

d) Now we have to add all those values:

0.00813604 + 0.00002304 + 0.00512656 + 0.00190969 + 0.01327104 + 0.00000169 + 0.00743044 + 0.01580049 + 0.00037636 = 0.05207535

e) Now we divide that result by the total number of values (they are nine measurements):

0.05207535/9 =

User Meraj Al Maksud
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