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Viktor [21]
3 years ago
14

the local bookstore is having a sole on used books . nate bought 3 hardcover books and 7 paperback books and spent 29.50. tia bo

ught 2 hardcover books and 5 paperback books and spent 20.50. what is the cost of a hardcover book
Mathematics
1 answer:
Mkey [24]3 years ago
6 0
The first thing we must do for this case is to define variables.
 We have then:
 x = cost of a hardcover book
 y = cost of a paperback book
 We write the system of equations:
 3x + 7y = 29.50
 2x + 5y = 20.50
 The solution to the system is:
 x = 4 $
 y = 2.5 $
 Answer:
 the cost of a hardcover book is $ 4
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8, 10, 12

A helpful equation:
x+x+1+x+2 = 30

Combine like terms
3x + 3 = 30

Subtract 3 from each side
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Divide each side by to isolate x
x = 9

x = 9. However, 9 is not an even number. Let’s subtract 1 from 9 to get the first even number.

The first number is 8. The best two even numbers after 8 are 10 and 12.

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3 years ago
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Answer:

15cm

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What is the LCM of 8 and 10
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2 years ago
The Paralyzed Veterans of America is a philanthropic organization that relies on contributions. They send free mailing labels an
lions [1.4K]

Answer:

Confidence interval:  (0.04649,0.04913)

Step-by-step explanation:

We are given the following in the question:

Sample size, n =  100,000

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\hat{p} = \dfrac{x}{n} = \dfrac{4781}{100000} = 0.04781


95% Confidence interval:

\hat{p}\pm z_{stat}\sqrt{\dfrac{\hat{p}(1-\hat{p})}{n}}

z_{critical}\text{ at}~\alpha_{0.05} = 1.96

Putting the values, we get:

0.04781
\pm 1.96(\sqrt{\dfrac{0.04781
(1-0.04781
)}{100000}})\\\\=0.04781
\pm 0.00132\\\\=(0.04649,0.04913)

is the required 95% confidence interval  for the true proportion of their entire mailing list who may donate.

3 0
3 years ago
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Answer:

405

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