Question

Grip is applied to produce normal surface forces that compress the object being gripped and the following data on grip strength (N) for a sample of 40 individuals:
16 33 66 95 111 135 151 189 220 238

18 41 68 98 118 145 168 190 229 244

18 54 87 106 127 147 172 200 230 259

26 56 91 109 127 149 183 210 233 294

(1) Make a relative frequency table of the data using groups 0−49, 50−99, ... technically, such groups are known as bins.

(2) Draw a frequency histogram of the data

(3) Calculate the sample mean and the sample median, and compare these two values. Which of these two values is more ‘informative’?

(4) Calculate the range and the interquartile range of the data. Which of these two values is more relevant?

(5) Calculate the sample variance, the sample standard deviation and the coefficient of variation.

Answer 1

Sample Mean=136.275, Median=131

The distribution is more densely distributed to the right. The distribution looks like a right skewed. Hence, median is more informative

4)Range=max-min=294-16=276

IQR=Q3-Q1=192.5-82.25=110.25

5)Variance=5729.54, SD=75.69

Coeff of variation=75.69/136.275=0.555