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2 years ago

14

The height of a cylinder is three times the diameter of the base. The surface area of the cylinder is 126 PI squared feet. What

is the radius of the base?

1 answer:

lozanna [386]2 years ago

3 0

30

you have to do the math of 9x2=18 then you add 12 to your answer and your answer is 30

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In a study of government financial aid for college students, it becomes necessary to estimate the percentage of full-time coll

ICE Princess25 [194]

Answer:

a) n = 1037.

b) n = 1026.

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:

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

99% confidence level

So $\alpha = 0.01$ , z is the value of Z that has a pvalue of $1 - \frac{0.01}{2} = 0.995$ , so $Z = 2.575$ .

(a) Assume that nothing is known about the percentage to be estimated.

We need to find n when M = 0.04.

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

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

$0.04 = 2.575\sqrt{\frac{0.5*0.5}{n}}$

$0.04\sqrt{n} = 2.575*0.5$

$(\sqrt{n}) = \frac{2.575*0.5}{0.04}$

$(\sqrt{n})^{2} = (\frac{2.575*0.5}{0.04})^{2}$

$n = 1036.03$

Rounding up

n = 1037.

(b) Assume prior studies have shown that about 55% of full-time students earn bachelor's degrees in four years or less.

$\pi = 0.55$

So

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

$0.04 = 2.575\sqrt{\frac{0.55*0.45}{n}}$

$0.04\sqrt{n} = 2.575*\sqrt{0.55*0.45}$

$(\sqrt{n}) = \frac{2.575*\sqrt{0.55*0.45}}{0.04}$

$(\sqrt{n})^{2} = (\frac{2.575*\sqrt{0.55*0.45}}{0.04})^{2}$

$n = 1025.7$

Rounding up

n = 1026.

6 0

2 years ago

A property agent charges a commission of 2.5% on the selling price of a house. If the agent sells a house $650000, find the amou

nadya68 [22]

650000(0.025) = $16,250

8 0

2 years ago

Read 2 more answers

Help asap! Please! Much appreciated!

stiv31 [10]

Area of the parallelogram = 20 x 16 = 320
Area of the triangle on top = 1/2 x 20 x 8 = 80
Total = 320 + 80 = 400 square inches

5 0

2 years ago

Please help me. these problems<br>

jeyben [28]

Answer:

1st problem:

Converges to 6

2nd problem:

Converges to 504

Step-by-step explanation:

You are comparing to $\sum_{k=1}^{\infty} a_1(r)^{k-1}$

You want the ratio r to be between -1 and 1.

Both of these problem are so that means they both have a sum and the series converges to that sum.

The formula for computing a geometric series in our form is $\frac{a_1}{1-r}$ where $a_1$ is the first term.

The first term of your first series is 3 so your answer will be given by:

$\frac{a_1}{1-r}=\frac{3}{1-\frac{1}{2}}=\frac{3}{\frac{1}{2}=6$

The second series has r=1/6 and a_1=420 giving me:

$\frac{420}{1-\frac{1}{6}}=\frac{420}{\frac{5}{6}}=420(\frac{6}{5})=504$ .

3 0

2 years ago

PLSS HELP!! VERY EASY.

gogolik [260]

Answer:

35 ways

Step-by-step explanation:

Alex has 9 friends and wants to invite 5 friends. Since Alex requires two of his friends who are twins to come together to his birthday party, since the two of them form a group, the number of ways we can select the two of them to form a group of two is ²C₂ = 1 way.

Since we have removed two out of the nine friends, we are left with 7 friends. Also, two friends are already selected, so we are left with space for 3 friends. So, the number of ways we can select a group of 3 friends out of 7 is ⁷C₃ = 7 × 6 × 5/3! = 35 ways.

So, the total number ways we can select 5 friend out of 9 to party come to the birthday include two friends is ²C₂ × ⁷C₃ = 1 × 35 = 35 ways

3 0

2 years ago