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3 years ago

10

Carla is a US student. She is purchasing used textbooks, because she is balling on a budget (pro tip: don't ever buy new books)!

She purchased a math book and a reading book, and the total was $54. The price of the math book is $8 more than 3 times the cost of the reading book. What is the cost of each book?

1 answer:

k0ka [10]3 years ago

4 0

I think this is how you do it. Use x as the price of the reading book, then make it an equation. Let me know if you don’t understand any of the steps. Hope that helps!

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Circle T is shown. Line segment Q S is a diameters. Point R is opposite of point T. Lines are drawn from points Q and S to point

Juliette [100K]

The value of angle x of the given cyclic segment is; 49.5°

<h3>How to find the angle of an arc?</h3>

We are given the measure of the angle of arc QS as (4x – 18)°

Now, to find the measure of arc QS, this angle is to be equal to 180° and as such;

Thus;

(4x – 18)° = 180°

4x - 18 = 180

4x = 180 + 18

4x = 198

x = 198/4

x = 49.5°

The angle subtended by the arc at the center of a circle with center C is the angle of the arc. It is denoted by. m AB, where A and B are the endpoints of the arc. With the help of the arc length formula, we can find the measure of arc angle.

The formula to measure the length of the arc is;

Arc Length Formula (if angle θ is in degrees); s = 2πr (θ/360°)

Arc Length Formula (if θ is in radians) s = ϴ × r.

Thus, the value of x of the given cyclic segment is; 49.5°

Read more about arc angle at; brainly.com/question/2005046

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8 0

1 year ago

If the diameter of a circle is 6 inches, how long is the arc subtended by an angle measuring 70°?

yaroslaw [1]

Since the diameter of the circle is 6 inches, then the radius will be half that, or 3 inches,

$\bf \textit{arc's length}\\\\
s=\cfrac{r\pi \theta }{180} \quad 
\begin{cases}
r=radius\\
\theta =angle~in\\
\qquad degrees\\
------\\
r=3\\
\theta =70
\end{cases}\implies s=\cfrac{3\cdot \pi \cdot 70}{180}\implies s=\cfrac{7\pi }{6}$

6 0

3 years ago

A candidate for a US Representative seat from Indiana hires a polling firm to gauge her percentage of support among voters in he

UkoKoshka [18]

Answer:

a) The minimum sample size is 601.

b) The minimum sample size is 2401.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

The margin of error is:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

For this problem, we have that:

We dont know the true proportion, so we use $\pi = 0.5$ , which is when we are are going to need the largest sample size.

95% confidence level

So $\alpha = 0.05$ , z is the value of Z that has a pvalue of $1 - \frac{0.05}{2} = 0.975$ , so $Z = 1.96$ .

a. If a 95% confidence interval with a margin of error of no more than 0.04 is desired, give a close estimate of the minimum sample size that will guarantee that the desired margin of error is achieved. (Remember to round up any result, if necessary.)

This is n for which M = 0.04. So

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.04 = 1.96\sqrt{\frac{0.5*0.5}{n}}$

$0.04\sqrt{n} = 1.96*0.5$

$\sqrt{n} = \frac{1.96*0.5}{0.04}$

$(\sqrt{n})^2 = (\frac{1.96*0.5}{0.04})^2$

$n = 600.25$

Rounding up

The minimum sample size is 601.

b. If a 95% confidence interval with a margin of error of no more than 0.02 is desired, give a close estimate of the minimum sample size necessary to achieve the desired margin of error.

Now we want n for which M = 0.02. So

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.02 = 1.96\sqrt{\frac{0.5*0.5}{n}}$

$0.02\sqrt{n} = 1.96*0.5$

$\sqrt{n} = \frac{1.96*0.5}{0.02}$

$(\sqrt{n})^2 = (\frac{1.96*0.5}{0.02})^2$

$n = 2401$

The minimum sample size is 2401.

4 0

3 years ago

What is an expression equivalent to 5x+10 using the distributive property?

Crank

Answer:

5x + 10

Step-by-step explanation:

I did the math and checked. :)

5 0

3 years ago

8th grade solving systems

Serhud [2]

Answer:

(x+22) + x = 88

Step-by-step explanation:

if x is how much your friend collected, then how much you collected would be x + 22 because you collected 22 more then her. and if you add both of those together to get how much you collected together (the total) you get 88. so x (your friends sea shells) plus x+22 (your sea shells) is 88. tell me if you also need help solving the actual equation

you have x+22 + x = 88

you combine like terms, in this case the Xs

and you get 2x + 22 = 88

then you subtract 22 to both sides because you want to get x alone

and you get 2x = 88 - 22

which is 2x = 66

then you divide by 2 on both sides

and you get x = 66/2

and you get x = 33

5 0

3 years ago

Read 2 more answers