I need it ASAP, Questions are attached as a photo

3. Theresa has 20 coins that are dimes and quarters. Together

KiRa [710]

Answer:

15 dimes
5 quarters

Step-by-step explanation:

Let q represent the number of quarters Theresa has. Then the value of her coins is ...

0.25q + 0.10(20 -q) = 2.75

0.15q = 0.75 . . . . . . . . . subtract 2.00, collect terms

q = 0.75/0.15 = 5

Theresa has 5 quarters and 15 dimes.

3 0

3 years ago

What value in Vertex Form moves the graph up?

Leno4ka [110]

Changing from negative to positive

6 0

2 years ago

Find the total surface area of this cone.<br> leave your answer in terms of pi<br> R=3<br> L=4

Yuliya22 [10]

Answer:

total surface area of cone is πr (r+l)

22/7 x 3 (3+4)

22/7*3 (7)

22 x 3 ( as 7 that was divided by 22 was cut out with 7 in the bracket)

hence,

TSA of cone = 66pi

8 0

2 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

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

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