8. The average age of 3 boys is 15 yrs. But if one is not considered,
2 answers:
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Given :
Initial length of electric cable needed, .
Later, Sally is told that the homeowner has decide to cut back from a three-car garage to a two-car garage, which will eliminate two branch circuits, one of 23 feet and the other of 34 feet.
To Find :
How many feet of wire will be needed now.
Solution :
Wire needed is given by :
Required = Total wire - ( length of 1nd branch + length of 2nd branch )
Required = 550 - ( 23 + 34 )
Required = 550 - ( 57 ) ft
Required = 443 ft
Therefore, length of wire required is 443 ft.
Hence, this is the required solution.
Answer:
Step-by-step explanation:
The standard deviation is the square root of the variance, and the variance is found by using the mean. So we will do that first. I will use the population variance as opposed to the sample variance since our set of numbers is small.
The mean: 8 + 12 + 15 + 17 + 18 = 70 and divide that by 5 to get
and use this to find the variance in the formula:
it is a bit difficult to enter that formula in correctly, but here's how it works mathematically:
Squaring this ensures us that we don't end up with zero, which would be useless.
so
which means that the standard deviation is
s = 3.633
(If you do it with n-1 = 4 in the denominator of the variance, you get a standard deviation of 4.062)