Statistics homework help. Mean, Median, and Mode

Find
the mean, median, mode, range, interquartile range, and standard deviation of the following two examples.

Example 1

X (income) No. of persons
200 24
250 26
180 16
300 20
350 6
280 30

Solution

X (income) No. of persons Fx CF (x-m)^2 (x-m)^2*f
180 16 2880 16 5108.73 81739.75
200 24 4800 40 2649.72 63593.23
250 26 6500 66 2.18 56.60
280 30 8400 96 813.65 24409.57
300 20 6000 116 2354.64 47092.72
350 6 2100 122 9707.09 58242.57
Total 122 30680 20636.01 275134.43

 
Mean: 251.47
Median: 250
Mode: 280
Range: 170
Interquartile Range: 30
Standard Deviation: 47.49
 

Example 2

X (income) No. of persons Cumulative frequency (cf)
180 16 16
200 24 40
250 26 66
280 30 96


Solution

X (income) No. of persons Cumulative frequency (cf) xf (x-m)^2 (x-m)^2*f
180 16 16 2880 3047.96 48767.36
200 24 40 4800 1239.63 29751.04
250 26 66 6500 218.79 5688.63
280 30 96 8400 2006.29 60188.80
Total 96 218 22580 6512.67 144395.83

 
Mean: 235.21
Median:  250
Mode: 280
Range: 100
Interquartile Range: 100
Standard Deviation: 38.78
 
 
 
 

Statistics homework help