the weights in pounds of some male and female dogs at an animal shelter are listed below.\nmale: 6, 12, 15…

the weights in pounds of some male and female dogs at an animal shelter are listed below.\nmale: 6, 12, 15, 25, 46, 75, 10, 82, 103\nfemale: 4, 11, 14, 20, 44, 65, 8, 76, 96\nwhich statement is true?\nthe standard deviation of male dogs is greater than the standard deviation of female dogs by approximately 4.2.\nthe standard deviation of female dogs is greater than the standard deviation of male dogs by approximately 2.5.\nthe standard deviation of male dogs is greater than the standard deviation of female dogs by approximately 2.5.\nthe standard deviation of female dogs is greater than the standard deviation of male dogs by approximately 4.2.
Answer
Explanation:
Step1: Calculate mean of male dogs
Let (x_{male}={6, 12, 15, 25, 46, 75, 10, 82, 103}), (\bar{x}_{male}=\frac{6 + 12+15+25+46+75+10+82+103}{9}=\frac{374}{9}\approx41.56)
Step2: Calculate variance of male dogs
(s_{male}^2=\frac{\sum_{i = 1}^{9}(x_{i}-\bar{x}{male})^2}{9 - 1}) ((6 - 41.56)^2+(12 - 41.56)^2+(15 - 41.56)^2+(25 - 41.56)^2+(46 - 41.56)^2+(75 - 41.56)^2+(10 - 41.56)^2+(82 - 41.56)^2+(103 - 41.56)^2) (=(- 35.56)^2+(-29.56)^2+(-26.56)^2+(-16.56)^2+(4.44)^2+(33.44)^2+(-31.56)^2+(40.44)^2+(61.44)^2) (=1264.51+873.89+705.43+274.23+19.71+1118.23+995.03+1635.39+3774.87) (=\frac{10661.3}{8}\approx1332.66) (s{male}=\sqrt{1332.66}\approx36.5)
Step3: Calculate mean of female dogs
Let (x_{female}={4, 11, 14, 20, 44, 65, 8, 76, 96}), (\bar{x}_{female}=\frac{4+11+14+20+44+65+8+76+96}{9}=\frac{338}{9}\approx37.56)
Step4: Calculate variance of female dogs
(s_{female}^2=\frac{\sum_{i = 1}^{9}(x_{i}-\bar{x}{female})^2}{9 - 1}) ((4 - 37.56)^2+(11 - 37.56)^2+(14 - 37.56)^2+(20 - 37.56)^2+(44 - 37.56)^2+(65 - 37.56)^2+(8 - 37.56)^2+(76 - 37.56)^2+(96 - 37.56)^2) (=(-33.56)^2+(-26.56)^2+(-23.56)^2+(-17.56)^2+(6.44)^2+(27.44)^2+(-29.56)^2+(38.44)^2+(58.44)^2) (=1126.27+705.43+555.07+308.35+41.47+752.95+873.89+1477.63+3415.23) (=\frac{9256.2}{8}\approx1157.03) (s{female}=\sqrt{1157.03}\approx34.0)
Step5: Compare standard - deviations
(s_{male}-s_{female}=36.5 - 34.0 = 2.5)
Answer:
The standard deviation of male dogs is greater than the standard deviation of female dogs by approximately 2.5.