The variance is the total of the squared distances of the given data from the mean. 
This can be calculated through the equation,
        
                            σ² = summation of X² / N  - μ²
where σ² is the variance X's are the data, N is the number of terms, and μ is the mean.
   summation of X² = 100² + 100² + 120² + 120² + 180² = 81200
                          N = 5
                                        μ = (100 + 100 + 120 + 120 + 180) / 5
                                         μ = 124
Substituting these values to the equation for variance,
                                 
                              σ² = (81200/5) - 124² = 864
Thus, the variance is equal to 864. 
        
                    
             
        
        
        
Answer:
1.75
Step-by-step explanation:
0.009÷0.004- =
=
2.25-0.5=
1.75
 
        
             
        
        
        
9514 1404 393
Answer:
   a) 600
   b) see below
   c) 1.26 hours
Step-by-step explanation:
a) The value of y when x=0 is the coefficient of the exponential term:
   y = 600·3^(-0) = 600·1 = 600
There were 600 atoms to start.
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b) see attached for a graph
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c) The graph shows 150 atoms at t = 1.26, about 1.26 hours after the start of time counting.
If you want to find that value algebraically, substitute for y and solve for x. Logarithms are involved.
   150 = 600·3^(-x)
   150/600 = 3^(-x)
   log(1/4) = -x·log(3)
   x = -log(1/4)/log(3) = log(4)/log(3) ≈ 1.2618595
After about 1.26 hours, there were 150 atoms.
 
        
             
        
        
        
1:105::25:X
105*25whole divided by 1*X
2625
        
                    
             
        
        
        
<h3>
Answer:  120 degrees</h3>
==============================================
Work Shown:
n = number of sides = 6
i = measure of interior angle
i = 180(n-2)/n
i = 180(6-2)/6
i = 180(4)/6
i = 720/6
i = 120
Each interior angle of this regular hexagon is 120 degrees.
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Alternative Approach:
E = exterior angle
E = 360/n
E = 360/6
E = 60
Each exterior angle of this regular hexagon is 60 degrees
i+E = 180
i = 180-E
i = 180-60
i = 120
We get the same answer.