Answer:
[tex](a)\ \bar x = 1.19[/tex]
[tex](b)\ \sigma_x = 0.18[/tex]
Step-by-step explanation:
Given
[tex]n = 4[/tex]
[tex]x: 1.45\ 1.19\ 1.05\ 1.07[/tex]
Solving (a): The mean
This is calculated as:
[tex]\bar x = \frac{\sum x}{n}[/tex]
So, we have:
[tex]\bar x = \frac{1.45 + 1.19 + 1.05 + 1.07}{4}[/tex]
[tex]\bar x = \frac{4.76}{4}[/tex]
[tex]\bar x = 1.19[/tex]
Solving (b): The standard deviation
This is calculated as:
[tex]\sigma_x = \sqrt{\frac{\sum(x - \bar x)^2}{n - 1}}[/tex]
So, we have:
[tex]\sigma_x = \sqrt{\frac{(1.45 -1.19)^2 + (1.19 -1.19)^2 + (1.05 -1.19)^2 + (1.07 -1.19)^2}{4 - 1}}[/tex]
[tex]\sigma_x = \sqrt{\frac{(0.1016}{3}}[/tex]
[tex]\sigma_x = \sqrt{0.033867}[/tex]
[tex]\sigma_x = 0.18[/tex]