Question

2.4.15 The ages (in years) of a random sample of shoppers at a gaming store are shown. Determine the range, mean, variance, and standard deviation of the sample data set 12, 21, 23, 15, 19, 18, 21, 18, 13, 18 The range is 11 (Simplify your answer.) The mean is 17.8 (Simplify your answer. Round to the nearest tenth as needed.) The variance is (Simplify your answer. Round to the nearest hundredth as needed.) Enter your answer in the answer box and then click Check Answer 1 Dart remaining Clear All Check An Reflect in ePortfolio

Answer 1

(a)

The Range = Maximum - Minimum

               = 23 - 12 = 11

So,

Answer is:

11

(b)

The mean is given by:

$\bar{x}=\frac{\sum_{i=1}^{10}x_{i}}{10}=\frac{178}{10}=17.8$

So,

Answer is:

17.8

(c)

From the give data, the following Table is calculated:

x	x - $\bar{x}$	(x - $\bar{x}$ )2
12	-5.8	33.64
21	3.2	10.24
23	5.2	27.04
15	-2.8	7.84
19	1.2	1.44
18	0.2	0.04
21	3.2	10.24
18	0.2	0.04
13	-4.8	23.04
18	0.2	0.04
Total		113.60

The Variance is given by:

$s^{2}=\frac{113.6}{9}=12.62$

So,

Answer is:

12.62