By definition, the volume of a sphere is given by:
V = (4/3) * (pi) * (r ^ 3)
where,
r: radius of the sphere.
Substituting we have:
V = (4/3) * (pi) * ((3) ^ 3) = 113.08 in ^ 3
answer
the best estimate for the volume of air in the balloon in cubic inches is
C. 113.1

3 0

2 years ago

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Seven - twelfths of a new dress has been sewn. Chelsea did 3/7 of the sewing. How much of the dress did Chelsea sew?

galina1969 [7]

1/4, because 7/12×3/7=1/4

7 0

3 years ago

Caroline and 2 friends are going to the mall on a bus. In how many different orders can the girls get into the front of the bus?

melisa1 [442]

3!, or 1*2*3, or 6. Thus is answered by the factorial function (!)

8 0

2 years ago

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A 90 percent confidence interval is to be created to estimate the proportion of television viewers in a certain area who favor m

Dominik [7]

Answer:

This means that the first interval, with 9000 viewers, is 3 times as narrower as the second interval, with 1000 viewers.

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 width of the interval is:

$W = 2z\sqrt{\frac{\pi(1-\pi)}{n}}$

In this sample:

Two 90% intervals, with different lenghts. So both have the same values for z an $\pi$

Interval A:

9000 viewers.

So the width is

$W_{A} = 2z\sqrt{\frac{\pi(1-\pi)}{9000}}$

Interval B:

100 viewers

So the width is

$W_{B} = 2z\sqrt{\frac{\pi(1-\pi)}{1000}}$

Relationship between the widths:

$R = \frac{W_{A}}{W_{B}} = \frac{2z\sqrt{\frac{\pi(1-\pi)}{9000}}}{2z\sqrt{\frac{\pi(1-\pi)}{1000}}} = \frac{\sqrt{1000}}{\sqrt{9000}} = \frac{\sqrt{1}}{\sqrt{9}} = \frac{1}{3}$

This means that the first interval, with 9000 viewers, is 3 times as narrower as the second interval, with 1000 viewers.

8 0

3 years ago