The best answer is C : The sum of the measures of two angles os 180 degrees .
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Charlie's Carpets:
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Carpet : $18/yd
Installation: $2/yd
Discount: 20% x $18 = 0.2 x 18 = $3.60
Carpet Price after discount = $18 - $3.60 = $14.40/yd²
Carpet Price with installation $14.40 + $2 = $16.40/yd²
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Cindy's Carpet
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Carpet = $18/yd²
Discount = 10% = 0.1 x $18 = $1.80
Price after Discount = $18 - $1.80 = $16.20/yd²
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Summary:
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Charlie's Carpet = $16.40/yd²
Cindy's Carpet = $16.20/yd²
CIndy's Carpet is cheaper.
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Find Cost:
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Length = 19 x 1/3 = 19/3 yards
Width = 12 x 1/3 = 4 yards
19/3 x 4 = 25 1/3 yd²
Cost = 25 1/3 x $16.20 = $410.40
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Answer: Cindy's Carpet is cheaper and it will cost $410.40.
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Answer:

And we can solve this using the following z score formula:

And if we use this formula we got:

So we can find this probability equivalently like this:

Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the heights of a population, and for this case we know the distribution for X is given by:
Where
and
We select n =100. Since the distribution for X is normal then we know that the distribution for the sample mean
is given by:
We want this probability:

And we can solve this using the following z score formula:

And if we use this formula we got:

So we can find this probability equivalently like this:

Answer:
19.32
Step-by-step explanation:
One way to find the missing number is to get the value of the left side of the equation first.
8.4(1.5 + 2.3) = 31.92
Now we need to take that value and subtract it to the value on the right side of the equation.
31.92 - 12.6 = 19.32
So we have:
8.4(1.5 + 2.3) = 12.6 + 19.32
31.92 = 31.92