In addition to mean and sample size you will need the individual scores.
The formula for standard deviation is:
S^2 = E(X-M)^2/N-1
Here's an example:
Data set: 4,4,3,1
Mean: 3
Sample size: 4
First, put the individual scores one after the other and subtract the mean from it.
4 - 3 = 1
4 - 3 = 1
3 - 3 = 0
1 - 3 = -2
Second, square the answers you got from step 1.
1^2 = 1
1^2 = 1
0^2 = 0
-2^2 = 4
Third, plug the values from step 2 into the formula.
S^2 = (1+1+0+4)/(4-1) = 6/3 = 2
Standard deviation = 2
Answer:
hope this helps
Step-by-step explanation:
x = 7
Answer:
Step-by-step explanation:
step 1
Find the area of the circle
The area of the circle is equal to
we have
substitute
step 2
we know that
The area of a circle subtends a central angle of 2π radians
so
using proportion
Find out the area of a sector with a central angle of 8 π/11 radians
C = 2πr
r = radius
c = circumference = 18
Plug in the corresponding numbers with variables.
18 = 2πr
Isolate the r. Divide 2 and π from both sides
(18)/2π = (2πr)/2π
9/π = r
C/π = r is your formula to finding r.
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