Variance = summation of (x - mean)^2 all divided by the number of dataset.
mean = (17 + 5 + 11 + 1 + 11)/5 = 9
Variance = [(17 - 9)^2 + (5 - 9)^2 + (11 - 9)^2 + (1 - 9)^2 + (11 - 9)^2]/5 = (8^2 + (-4)^2 + 2^2 + (-8)^2 + 2^2}/5 = (64 + 16 + 4 + 64 + 4)/5 = 152/5 = 30.4
Answer:
-4/5
Step-by-step explanation:
The Answer would be x=72. Why? Because

is your %. You Cross multiply 240 * 30 = 100x
240 time 30 = 7200. you want x to be alone so you do 7200 divided by 100 equaling 72. So you get x=72.
Given:
The data points are:
(1, 0), (2, 3), (3,1), (4,4), (5,5)
To find:
The equation of best fit line in the form of
and then find the value of b.
Solution:
The general form of best fit line is:
...(i)
Where, m is the slope of best fit line and b is the y-intercept of the line.
Using the graphing calculator, we get the equation for the best fit line and the equation is
...(ii)
On comparing (i) and (ii), we get

Therefore, the value of b is equal to -0.7.
Initial cost of the jet ski = $925
Percentage of depreciation per year = 15%
Number of years after which the cost of the jetski has to be determined = 7
Then
Depreciated Value = Initial cost( 1 - percentage of depreciation) ^number of years
= 925( 1 - 15%)^7
= 925( 1 - 15/100)^7
= 925(1 - 0.15)^7
= 925(0.85)^7
= 925 *(0.85)^7
= 925 * 0.3206
= 296.53 dollars
So the depreciated cost of the jet ski after 7 years will be $296.53