Question

The following data are the distances between 20 retail stores and a large distribution center. The distances are in miles.

29; 38; 39; 40; 58; 67; 68; 69; 76; 85; 86; 95; 96; 96; 99; 106; 112; 127; 145; 150

Use a graphing calculator or computer to find the standard deviation and round to the nearest tenth.

Answer 1

Sr. no	X	(X - X̄)²
1	29	3030.50
2	38	2120.60
3	39	2029.50
4	40	1940.40
5	58	678.60
6	67	290.70
7	68	257.603
8	69	226.503
9	76	64.803
10	85	0.903
11	86	3.803
12	95	119.903
13	96	142.803
14	96	142.803
15	99	223.503
16	106	481.803
17	112	781.203
18	127	1844.703
19	145	3714.903
20	150	4349.403

	X	(X - X̄)²
total sum	1681	22444.95
n	20	20

mean =    ΣX/n =    1681.000   /   20   =   84.0500
                      
  
sample std dev =   √ [ Σ(X - X̄)²/(n-1)] =   √   (22444.95/19)   =       34.4