find the rate in the following problem Round the answer to the nearest hundredth of a percent. What percent of 85 is 10?

How can we find out the area of a sphere? explain in brief

USPshnik [31]

Step-by-step explanation:

Basically the area of sphere is 4πr² where r is radius whose value is distance from centre to the edge of the given sphere whereas π (pi) whose value is 3.14 or 22/7. It is defined as the ratio between circle's circumference and it's diameter. But are you aware about the area of circle?? Actually that is πr². If you notice carefully you'll find that area of sphere is 4 times the area of circle. So, if you're provided with the area of circle you can simply multiply the value with 4 to get the area of sphere. But if not, then simply plugin the value of radius and pi in 4πr² to find out the area of sphere.

But since the formula is almost same then how they're different? Well the difference between a sphere and a circle is because of two-dimensional and three-dimensional shape. A circle is a two-dimensional flat shape figure whereas a sphere is a three-dimensional shape.

Talking about the unit of sphere. The unit we use is always the same as the units of radius i.e. cm or m. Since, it is the square of the radius in the given formula, then the unit is also the square of the units, or cm² or m².

6 0

2 years ago

Read 2 more answers

If you ride a pterodactyl for 3 hours at 10 mph and then ride a stegosaurus for 1 hour at 2 mph, what would be your average spee

g100num [7]

Answer:

8 mph

Step-by-step explanation:

The equation for average speed is:

$average\ speed=\frac{total\ distance}{total\ time}$

Let's start by finding the distance for each animal:

$d=st\\d=3h*10\frac{m}{h}\\d=30m$

$d=st\\d=1h*2\frac{m}{h}\\d=2m$

Now, we can find the average speed:

$average \ speed=\frac{30mi+2mi}{3hr+1hr}=\frac{32mi}{4hr}=8\frac{mi}{h}$

8 mph

3 0

3 years ago

A box weighs 90 grams. Write down, in terms of b, the weight of the boxes.

antiseptic1488 [7]

Answer:

'

Step-by-step explanation:

'

6 0

3 years ago

Thirty-seven percent of all Americans drink bottled water more than once a week (Natural resources Defense Council, December 4,

lesantik [10]

Answer:

a) The sampling distribution for n=540 has a mean sample proportion of p=0.37 and a standard deviation of σs=0.0208.

b) probability = 0.99998

d) probability = 0.99874

e) You gain 0.12% in probability for an increase of 80% in sample size.

The increase in sample size is not justified by the increase in probability, for this margin of error (Δp=0.09).

Step-by-step explanation:

a) We have a known population proportion π=0.37 and we have to describe the sampling distribution when the sample size is n=540.

The mean sample proportion is expected to be the same as the population proportion:

$\bar p = \pi = 0.37$

The standard deviation of the sampling will be the population standard deviation divided by the square root of the sample size:

$\sigma_s=\dfrac{\sigma}{\sqrt{n}}=\sqrt{\dfrac{p(1-p)}{n}}=\sqrt{\dfrac{0.37*0.63}{540}}=\sqrt{0.000431667}=0.0208$

Then, we can say that the sampling distribution will have a p=0.37 and a standard deviation σs=0.0208.

b) We have to calculate the probability that the sample proportion will be within 0.09 of the population proportion.

We can calculate the z-value as:

$z_1=\dfrac{p_1-\bar p}{\sigma_s}=\dfrac{0.09}{0.0208}=4.3269\\\\\\z_2=\dfrac{p_2-\bar p}{\sigma_s}=\dfrac{-0.09}{0.0208}=-4.3269$

As the distribution is symmetrical, we can calculate the probabilty that he sample proportion will be within 0.09 of the population proportion as:

$P(|p-\bar p|$

probability = 0.99998

d. Now the sample is smaller (n=300), so the standard deviation of the samping distribution:

$\sigma_s=\dfrac{\sigma}{\sqrt{n}}=\sqrt{\dfrac{p(1-p)}{n}}=\sqrt{\dfrac{0.37*0.63}{300}}=\sqrt{0.000777}=0.0279$

We have to recalculate the z-scores:

$z_1=\dfrac{p_1-\bar p}{\sigma_s}=\dfrac{0.09}{0.0279}=3.2258\\\\\\z_2=\dfrac{p_2-\bar p}{\sigma_s}=\dfrac{-0.09}{0.0279}=-3.2258$

And the probability is:

$P(|p-\bar p|$

probability = 0.99874

e. The increase in sample size is 80%

$\Delta n\%=\dfrac{n_1}{n_2}-1=\dfrac{540}{300}-1=1.8-1=0.8=80\%$

and the increase in probability is 0.12%

$\Delta P\%=\dfrac{P_1}{P_2}-1=\dfrac{0.99998}{0.99874}-1=1.0012-1=0.0012=0.12\%$

You gain 0.12% in probability for an increase of 80% in sample size.

The increase in sample size is not justified by the increase in probability, for this margin of error (Δp=0.09).

7 0

3 years ago

Does the line whose equation is 4/3 x + 8 pass through the point (9,20)

sergey [27]

Answer: yes

Step-by-step explanation: slope is 4/3 and y intercept is 8

m= Y-20/0-9

4/3= y-20/-9

4/3 x -9 = y-20

-12 = y-20

Y=20-12

Y=8

5 0

3 years ago