Answer:
24.2(to the nearest tenth)
Step-by-step explanation:
The question is ungrouped data type
standard deviation =√ [∑ (x-μ)² / n]
mean (μ)=∑x/n
=
=33.3
x-μ for data 5, 5, 6, 12, 13, 26, 37, 49, 51, 56, 56, 84 will be
-28.3, -28.3, -27.3, -21.3, -7.3, 3.7, 15.7,17.7, 22.7,22.7,50.7
(x-μ)² will be 800.89, 800.89,745.29,453.69,53.29,13.69,246.49,313.29,515.29,515.29,2570.49
∑ (x-μ)² will be = 7028.59
standard deviation = √(7028.59 / 12)
=24.2
Answer: Choice B
a = 42, b = 5, c = 28, d = 33, e = 10
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Explanation:
Refer to the diagram below. We have a table of values in which some values (if not most) are unknown. We have variables as placeholders until we can figure out which numbers replace them.
Along the bottom row, we see that 70+e = 80, which solves to e = 10. I subtracted 70 from both sides.
That must mean the answer is between choice A or choice B.
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Since e = 10, and b+5 = e (third column), we can replace the 'e' with 10 to get the equation b+5 = 10. That solves to b = 5. This rules out choice A.
The final answer is choice B
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If you want to keep going to find a, c and d, then let's solve a+b = 47 which is the same as a+5 = 47 after replacing letter b with 5.
a+5 = 47 solves to a = 42 after subtracting both sides by 5.
Then along the first column, we see that a+c = 70 which is the same as 42+c = 70. Isolating c gets us c = 28
Lastly, c+5 = d is shown along the second row. Plug in c = 28 to find that d = c+5 = 28+5 = 33
So overall we have:
a = 42, b = 5, c = 28, d = 33, e = 10
