the ages (in years) of a random sample of shoppers at a gaming store are shown. determine the range, mean…

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, 18, 23, 15, 17, 17, 19, 16, 13, 19 the range is (simplify your answer.)
Answer
Explanation:
Step1: Find the range
Range = Max - Min. Max = 23, Min = 12. So Range = 23 - 12 = 11.
Step2: Calculate the mean
Mean $\bar{x}=\frac{\sum_{i = 1}^{n}x_{i}}{n}$. Here $n = 10$, $\sum_{i=1}^{10}x_{i}=12 + 18+23+15+17+17+19+16+13+19=169$. So $\bar{x}=\frac{169}{10}=16.9$.
Step3: Calculate the variance
The formula for sample - variance $s^{2}=\frac{\sum_{i = 1}^{n}(x_{i}-\bar{x})^{2}}{n - 1}$. $(12-16.9)^{2}=(-4.9)^{2}=24.01$, $(18 - 16.9)^{2}=(1.1)^{2}=1.21$, $(23-16.9)^{2}=(6.1)^{2}=37.21$, $(15-16.9)^{2}=(-1.9)^{2}=3.61$, $(17-16.9)^{2}=(0.1)^{2}=0.01$, $(17-16.9)^{2}=(0.1)^{2}=0.01$, $(19-16.9)^{2}=(2.1)^{2}=4.41$, $(16-16.9)^{2}=(-0.9)^{2}=0.81$, $(13-16.9)^{2}=(-3.9)^{2}=15.21$, $(19-16.9)^{2}=(2.1)^{2}=4.41$. $\sum_{i = 1}^{10}(x_{i}-16.9)^{2}=24.01+1.21+37.21+3.61+0.01+0.01+4.41+0.81+15.21+4.41 = 90.9$. $s^{2}=\frac{90.9}{9}=10.1$.
Step4: Calculate the standard deviation
The standard - deviation $s=\sqrt{s^{2}}=\sqrt{10.1}\approx3.18$.
Answer:
Range: 11 Mean: 16.9 Variance: 10.1 Standard deviation: $\approx3.18$