Question

2. According to the United Nations, the infant mortality rate (number of infants died before the age of one per 1000 live births) in ten most populous were as follows:

Country	Infant Mortality Rate
China	30
India	57
United States	6.9
Indonesia	23

Brazil	24
Pakistan	67
Russia	16
Bangladesh	38
Japan	2.9
Nigeria	79

Find the values for each of the following: range, variance, and standard deviation

Answer 1

Range = Maximum value - Minimum value

= 79 - 2.9

= 76.1

Range = 76.1

Mean = X / n

= (30 + 57 + 6.9 + 23 + 24 + 67 + 16 + 38 + 2.9 + 79) / 10

= 343.8 / 10

= 34.38

Variance = ( X² - n * mean² ) / n - 1

= [ (30² + 57² + 6.9² + 23² + 24² + 67² + 16² + 38² + 2.9² + 79² ) - 34.38² ] / 9

= 657.7973

Variance = 657.7973

Standard deviation = Sqrt [ Variance ]

= Sqrt [ 657.7973 ]

= 25.6476

Standard deviation = 25.6476