Question

Find the​ (a) mean,​ (b) median,​ (c) mode, and​ (d) midrange for the given sample data. Fourteen different​ second-year medical students measured the blood pressure of the same person. The systolic readings​ (in mmHg) are listed below.

131 140 145 143 131 136 131 147 120 140 120 131 137 124

Answer 1

Solution:-

a.Mean= Sum of observations/ total number of observations

Sum(S)=131 +140 +145+ 143+ 131+ 136 +131+ 147+ 120 +140 +120+ 131 +137 +124=1876

Number of observations(N)=14

Therefore, Mean (M)= S/N=1876/14=134

b.Median (Middle value)

As there are even number of terms , hence the median is basically the mean of the two middle number's

i.e = (131+147) / 2 = 139

c.Mode (most occurucying term)

To find the mode , i.e the term occuring max number of time's we will first find the frequency of occurance of each term in the given series.

131: 4

140 : 2

145: 1

143: 1

136 :1

147:1

120 :2

137 :1

124:1

Hence clearly our mode is 131.

(d) midrange for the given sample data

131 140 145 143 131 136 131 147 120 140 120 131 137 124

Least number:- 124

Maximum number:- 147

Mid range = (least + max) / 2

(124+147)/2= 135.5