we are going to calculate the standard deviation for the following set of sample data. 9 12 1 10 14 1)…

we are going to calculate the standard deviation for the following set of sample data. 9 12 1 10 14 1) calculate the mean. $\bar{x}=$ 2) fill in the table below: fill in the differences of each data value from the mean, then the squared differences. \n|$x$|$x - \bar{x}$|$(x - \bar{x})^2$|\n|----|----|----|\n|9| | |\n|12| | |\n|1| | |\n|10| | |\n|14| | |\n| |$sum(x - \bar{x})^2=$| |\n3) calculate the sample standard deviation (s). $s=sqrt{\frac{sum(x - \bar{x})^2}{n - 1}}=$ (please round your answer to two decimal places)
Answer
Explanation:
Step1: Calculate the mean
The formula for the mean $\bar{x}$ of a sample $x_1,x_2,\cdots,x_n$ is $\bar{x}=\frac{\sum_{i = 1}^{n}x_i}{n}$. Here, $n = 5$, $x_1=9,x_2 = 12,x_3=1,x_4 = 10,x_5=14$. So, $\bar{x}=\frac{9 + 12+1+10+14}{5}=\frac{46}{5}=9.2$.
Step2: Fill in the table
For $x = 9$: $x-\bar{x}=9 - 9.2=-0.2$, $(x - \bar{x})^2=(-0.2)^2 = 0.04$. For $x = 12$: $x-\bar{x}=12 - 9.2 = 2.8$, $(x - \bar{x})^2=(2.8)^2=7.84$. For $x = 1$: $x-\bar{x}=1 - 9.2=-8.2$, $(x - \bar{x})^2=(-8.2)^2 = 67.24$. For $x = 10$: $x-\bar{x}=10 - 9.2 = 0.8$, $(x - \bar{x})^2=(0.8)^2=0.64$. For $x = 14$: $x-\bar{x}=14 - 9.2 = 4.8$, $(x - \bar{x})^2=(4.8)^2=23.04$. And $\sum(x - \bar{x})^2=0.04 + 7.84+67.24+0.64+23.04=98.8$.
Step3: Calculate the sample - standard deviation
The formula for the sample standard deviation $s$ is $s=\sqrt{\frac{\sum(x - \bar{x})^2}{n - 1}}$. Here, $n = 5$, so $s=\sqrt{\frac{98.8}{5 - 1}}=\sqrt{\frac{98.8}{4}}=\sqrt{24.7}\approx4.97$.
Answer:
- $\bar{x}=9.2$
| $x$ | $x-\bar{x}$ | $(x - \bar{x})^2$ |
|---|---|---|
| 9 | -0.2 | 0.04 |
| 12 | 2.8 | 7.84 |
| 1 | -8.2 | 67.24 |
| 10 | 0.8 | 0.64 |
| 14 | 4.8 | 23.04 |
| $\sum(x - \bar{x})^2 = 98.8$ |
- $s\approx4.97$