Answer:
-20
Step-by-step explanation:
-20
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Convert 76.8% to a decimal.
0.768 * x=40.32
Multiply 0.768 by x to get 0.768x.
0.768x=40.32
Multiply each term by 1 / 0.768 and simplify.
Cancel the common factor of 0.768.
x=40.32 / 0.768
Divide 40.32 by 0.768 to get 52.5
x=52.5
Step-by-step explanation:
Area of a circle = #r^2
1256 = 3.14 × r^2
r^2 = 1256/3.14
r^2 = 400
Square root of r = 20
Diameter = 2 × r = 2 × 20 = 40 inches
an equation for a circle has formula
(x-m)² + (y-n)² = r²
where (m,n) is its center
and r is its radius
so, the equation has center (4,3) and radius 4
the equation is derived from the pythagorean theorem
The standard deviation is 9.27. The typical heart rate for the data set varies from the mean by an average of 9.27 beats per minute.
<h3>How to determine the standard deviation of the data set?</h3>
The dataset is given as:
Heart Rate Frequency
60 1
65 3
70 4
75 12
80 8
85 15
90 9
95 5
100 3
Calculate the mean using
Mean = Sum/Count
So, we have
Mean = (60 * 1 + 65 * 3 + 70 * 4 + 75 * 12 + 80 * 8 + 85 * 15 + 90 * 9 + 95 * 5 + 100 * 3)/(1 + 3 + 4 + 12 + 8 + 15 + 9 + 5 + 3)
Evaluate
Mean = 82.25
The standard deviation is

So, we have:
SD = √[1 * (60 - 82.25)^2 + 3 * (65 - 82.25)^2 + 4 * (70 - 82.25)^2 + 12 * (75 - 82.25)^2 + 8 * (80 - 82.25)^2 + 15 * (85 - 82.25)^2 + 9 * (90 - 82.25)^2 + 5 * (95 - 82.25)^2 + 3 * (100 - 82.25)^2)]/[(1 + 3 + 4 + 12 + 8 + 15 + 9 + 5 + 3 - 1)]
This gives
SD = √85.9533898305
Evaluate
SD = 9.27
Hence. the standard deviation is 9.27. The typical heart rate for the data set varies from the mean by an average of 9.27 beats per minute.
Read more about standard deviation at:
brainly.com/question/4079902
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