Answer:
(a) [tex]\bar x= 1.583[/tex] -- Population Mean
(b) [tex]s = 1.032[/tex] --- Population standard deviation
(c) See Explanation
Step-by-step explanation:
Given:
Cigarette tax for 20 regions
Solving (a): The population mean
This is calculated as:
[tex]\bar x = \frac{\sum x}{n}[/tex]
[tex]\sum x = 1.36 + 1.70 + 2.50 + 0.45 + 1.18 + 0.64 + 3.46 + 0.57 + 2.00 + 0.80 + 1.60 +0.98 + 0.36 + 2.24 + 4.35 + 0.62 + 2.70 + 1.78 + 1.53 + 0.84[/tex]
[tex]\sum x = 31.66[/tex]
[tex]n = 20[/tex]
So, we have:
[tex]\bar x= \frac{31.66}{20}[/tex]
[tex]\bar x= 1.583[/tex]
Solving (b): The population standard deviation
This is calculated as:
[tex]s = \sqrt{\frac{\sum( x - \bar x)^2}{n}[/tex]
[tex]\sum (x -\bar x)^2 = (1.36 - 1.583)^2 + (1.70 - 1.583)^2+ (2.50 - 1.583)^2+ (0.45 - 1.583)^2+ (1.18 - 1.583)^2+ (0.64 - 1.583)^2+ (3.46 - 1.583)^2+ (0.57 - 1.583)^2+ (2.00 - 1.583)^2+ (0.80 - 1.583)^2+ (1.60 - 1.583)^2+(0.98 - 1.583)^2+ (0.36 - 1.583)^2+ (2.24 - 1.583)^2+ (4.35 - 1.583)^2+ (0.62 - 1.583)^2+ (2.70 - 1.583)^2+ (1.78 - 1.583)^2+ (1.53 - 1.583)^2+ (0.84- 1.583)^2[/tex]
[tex]\sum (x -\bar x)^2 = 21.29222[/tex]
So:
[tex]s = \sqrt{\frac{21.2922}{20}[/tex]
[tex]s = \sqrt{1.06461}[/tex]
[tex]s = 1.032[/tex]
Solving (c):
Population mean tells the average amount while the standard deviation represents the spread from the calculated mean
Option (4) is correct