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andrew-mc [135]

3 years ago

15

Four CDs and 4 DVDs cost $164. The cost of the 4 CDs is half the cost of the

1 answer:

pochemuha3 years ago

8 0

Answer:

Each CD cost $20.50

Step-by-step explanation:

You would divide the cost of the DVDs by 4: 164÷4=41

Now the CDs are half the cost of the DVDs so you would divide 41 by 2: 41÷2=20.50

Your answer would be $20.50

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There is only one angle measure , ∡JHF , which is 34 degrees . I have to find the measure of angle ∡FJH .

Minchanka [31]

the assumption here being that both lines JH and FH are tangent lines to the circle, if that's the case the external angle of 34° is the angle made by the equal tangents, meaning the triangle is an isosceles with twin sides.

In an isosceles triangle the twin sides make also twin angles, so the angles at J and F are twins, and they'd be 180° - 34° = 146° total, since they're twins, each one takes half, or 73°.

5 0

3 years ago

Read 2 more answers

Solve for x,<br> -3x = -15

Goshia [24]

Answer:

x=5

Step-by-step explanation:

so to isolate the x you dived the -3 to both sides

so it will now be

x=5 because a negative times or divided by a negative equals a positive so to prove that x=5

-3(5)=-15

which is true

5 0

3 years ago

Read 2 more answers

The following results come from two independent random samples taken of two populations.

photoshop1234 [79]

Answer:

$(a)\ \bar x_1 - \bar x_2 = 2.0$

$(b)\ CI =(1.0542,2.9458)$

$(c)\ CI = (0.8730,2.1270)$

Step-by-step explanation:

Given

$n_1 = 60$ $n_2 = 35$

$\bar x_1 = 13.6$ $\bar x_2 = 11.6$

$\sigma_1 = 2.1$ $\sigma_2 = 3$

Solving (a): Point estimate of difference of mean

This is calculated as: $\bar x_1 - \bar x_2$

$\bar x_1 - \bar x_2 = 13.6 - 11.6$

$\bar x_1 - \bar x_2 = 2.0$

Solving (b): 90% confidence interval

We have:

$c = 90\%$

$c = 0.90$

Confidence level is: $1 - \alpha$

$1 - \alpha = c$

$1 - \alpha = 0.90$

$\alpha = 0.10$

Calculate $z_{\alpha/2}$

$z_{\alpha/2} = z_{0.10/2}$

$z_{\alpha/2} = z_{0.05}$

The z score is:

$z_{\alpha/2} = z_{0.05} =1.645$

The endpoints of the confidence level is:

$(\bar x_1 - \bar x_2) \± z_{\alpha/2} * \sqrt{\frac{\sigma_1^2}{n_1}+\frac{\sigma_2^2}{n_2}}$

$2.0 \± 1.645 * \sqrt{\frac{2.1^2}{60}+\frac{3^2}{35}}$

$2.0 \± 1.645 * \sqrt{\frac{4.41}{60}+\frac{9}{35}}$

$2.0 \± 1.645 * \sqrt{0.0735+0.2571}$

$2.0 \± 1.645 * \sqrt{0.3306}$

$2.0 \± 0.9458$

Split

$(2.0 - 0.9458) \to (2.0 + 0.9458)$

$(1.0542) \to (2.9458)$

Hence, the 90% confidence interval is:

$CI =(1.0542,2.9458)$

Solving (c): 95% confidence interval

We have:

$c = 95\%$

$c = 0.95$

Confidence level is: $1 - \alpha$

$1 - \alpha = c$

$1 - \alpha = 0.95$

$\alpha = 0.05$

Calculate $z_{\alpha/2}$

$z_{\alpha/2} = z_{0.05/2}$

$z_{\alpha/2} = z_{0.025}$

The z score is:

$z_{\alpha/2} = z_{0.025} =1.96$

The endpoints of the confidence level is:

$(\bar x_1 - \bar x_2) \± z_{\alpha/2} * \sqrt{\frac{\sigma_1^2}{n_1}+\frac{\sigma_2^2}{n_2}}$

$2.0 \± 1.96 * \sqrt{\frac{2.1^2}{60}+\frac{3^2}{35}}$

$2.0 \± 1.96* \sqrt{\frac{4.41}{60}+\frac{9}{35}}$

$2.0 \± 1.96 * \sqrt{0.0735+0.2571}$

$2.0 \± 1.96* \sqrt{0.3306}$

$2.0 \± 1.1270$

Split

$(2.0 - 1.1270) \to (2.0 + 1.1270)$

$(0.8730) \to (2.1270)$

Hence, the 95% confidence interval is:

$CI = (0.8730,2.1270)$

8 0

3 years ago

David is three time as old as Joseph after 3 years David will be only twice as old as process will be there find their present a

kvasek [131]

Answer:

Joseph's present age=3 yrs

David's present age=9 yrs

Step-by-step explanation:

Let Joseph's present age be x.

David's present age=3x

__________________

Ater 3 yrs,

Joseph's age=x+3

David's age=2(x+3)

Also, we can add 3 to David's present age to get age After 3 yrs. So, David's age after 3 yrs would also be 3x+3.

Now, balance them.

3x+3=2(x+3)

3x+3=2x+6

x=3

D"s prsent age=9

J's present age=3

5 0

1 year ago

I need help with question 5 and its solve by subtitution

Bingel [31]

Y = 3x + 15
y = 2x + 8

3x + 15 = 2x + 8
-2x -2x
——————-
x + 15 = 8
-15 -15
—————-
x = -7

4 0

4 years ago