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.
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<h3>
Answer: Choice B</h3><h3>
y = x^2 + 7x + 1</h3>
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Proof:
A quick way to confirm that choice B is the only answer is to eliminate the other non-answers.
If you plugged x = 1 into the equation for choice A, you would get
y = -x^2 + 7x + 1
y = -1^2 + 7(1) + 1
y = -1 + 7 + 1
y = 7
We get a result of 7, but we want 9 to be the actual output. So choice A is out.
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Repeat for choice C. Plug in x = 1
y = x^2 - 7x + 1
y = 1^2 - 7(1) + 1
y = 1 - 7 + 1
y = -5
We can eliminate choice C (since again we want a result of y = 9)
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Finally let's check choice D
y = x^2 - 7x - 1
y = 1^2 - 7(1) - 1
y = 1 - 7 - 1
y= -7
so choice D is off the list as well
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The only thing left is choice B, so it must be the answer. It turns out that plugging x = 1 into this equation leads to y = 9 as shown below
y = x^2 + 7x + 1
y = 1^2 + 7(1) + 1
y = 1 + 7 + 1
y = 9
And the same applies to any other x value in the table (eg: plugging in x = 3 leads to y = 31, etc etc).
Answer:
x = 139
Step by Step Explanation:
Your answer would be, y= cos(x)+6
Answer:
a= 
or ≈ -3.66
Step-by-step explanation:
-(3a+4)=7
-3a-4=7
<em>Add 4 to both sides</em>
-3a=11
<em>Multiply both sides by -1</em>
3a= -11
Divide both sides by 3
a=
