Question

Given the following data set, what is the sample standard deviation, rounded to three decimal places. show steps using a TI 30XS calculator- thanks!

Height	# of people
63	20
67	30
68	25
70	10
74	5

Answer 1

Here x: Height and f: frequency that is number of people.

The formula to find the sample standard deviation is,

First find the mean

The formula to find mean is

Mean = 67.11

This calculations can be done is calculator TI 30XS

The table of calculation to find the standard deviation is,

x(height)	f (No. of people)	(x - mean)	(x - mean)2	(x - mean)2*f
63	20	63 - 67.11 = -4.11	(-4.11)2 = 16.8921	16.8921* 20 = 337.842
67	30	-0.11	0.0121	0.363
68	25	0.89	0.7921	19.8025
70	10	2.89	8.3521	83.521
74	5	6.89	47.4721	237.3605

The sum of last column is 678.889

Plug this value in the formula of standard deviation,

Sample standard deviation = 2.762