Answer this question please!

The circumference of Circle K is $\pi$ . The circumference of Circle L is $4\pi$ . Two circles, one labeled "Circle K" and the o

timurjin [86]

Answer:

Step-by-step explanation:

Given the circumference of Circle K = π

circumference of Circle L = 4π

Ratio of their circumferences = Ck/Cl

Ratio of their circumferences = π/4π

Ratio of their circumferences = 1/4 = 1:4

For their radii

C = 2πr

for circle k with circumference π

π = 2πrk

1 = 2rk

rk = 1/2

for circle l with circumference 4π

4π = 2πr

4 = 2r

r = 4/2

rl = 2

ratio

rk/rl = 1/2/2

rk/rl = 1/4 = 1:4

for the areas

Area of a circle = πr²

for circle k

Ak = π(1/2)²

Ak = π(1/4)

Ak = π/4

for circle l

Al = π(2)²

Al = 4π

Ratio of their areas

Ak/Al = π/4/(4π)

Ak/Al = π/16π

Ak/Al = 1/16 = 1:16

3 0

2 years ago

The price to ship a box varies directly as the weight of the box in pounds. A box that weighs 10 pounds costs $10.90 to ship.

xenn [34]

Well we can say 10.90/10 = the cost per pound to ship the item
we can infer this from the above text so
10.90/10 = 1.09.
So 1.09 * 37 = 40.33
$40.33
or 40 dollars and 33 cents to ship the second box with a weight of 37lb (pounds).

3 0

2 years ago

What is 25 divided 34

Minchanka [31]

Answer:

0.74

Step-by-step explanation:

5 0

2 years ago

If f(x) = –3x – 2, what is f(–5)?

Step2247 [10]

F(x) = -3x - 2
f(-5) = -3(-5) -2 = 15 - 2 = 13

3 0

2 years ago

New York City is the most expensive city in the United States for lodging. The room rate is $204 per night (USA Today, April 30,

Sever21 [200]

Answer:

a. 0.35197 or 35.20%; b. 0.1230 or 12.30%; c. 0.48784 or 48.78%; d. $250.20 or more.

Step-by-step explanation:

In general, we can solve this question using the <em>standard normal distribution</em>, whose values are valid for any <em>normally distributed data</em>, provided that they are previously transformed to <em>z-scores</em>. After having these z-scores, we can consult the table to finally obtain the probability associated with that value. Likewise, for a given probability, we can find, using the same table, the z-score associated to solve the value <em>x</em> of the equation for the formula of z-scores.

We know that the room rates are <em>normally distributed</em> with a <em>population mean</em> and a <em>population standard deviation</em> of (according to the cited source in the question):

$\\ \mu = \$204$ <em>(population mean)</em>

$\\ \sigma = \$55$ <em>(population standard deviation)</em>

A <em>z-score</em> is the needed value to consult the <em>standard normal table. </em>It is a transformation of the data so that we can consult this standard normal table to obtain the probabilities associated. The standard normal table has a mean of 0 and a standard deviation of 1.

$\\ z_{score}=\frac{x-\mu}{\sigma}$

After having all this information, we can proceed as follows:

<h3>What is the probability that a hotel room costs $225 or more per night? </h3>

1. We need to calculate the z-score associated with x = $225.

$\\ z_{score}=\frac{225-204}{55}$

$\\ z_{score}=0.381818$

$\\ z_{score}=0.38$

We rounded the value to two decimals since the <em>cumulative standard normal table </em>(values for cumulative probabilities from negative infinity to the value x) to consult only have until two decimals for z values.

Then

2. For a z = 0.38, the corresponding probability is P(z<0.38) = 0.64803. But the question is asking for values greater than this value, then:

$\\ P(z>038) = 1 - P(z$ (that is, the complement of the area)

$\\ P(z>038) = 1 - 0.64803$

$\\ P(z>038) = 0.35197$

So, the probability that a hotel room costs $225 or more per night is P(x>$225) = 0.35197 or 35.20%, approximately.

<h3>What is the probability that a hotel room costs less than $140 per night?</h3>

We follow a similar procedure as before, so:

$\\ z_{score}=\frac{x-\mu}{\sigma}$

$\\ z_{score}=\frac{140-204}{55}$

$\\ z_{score}= -1.163636 \approx -1.16$

This value is below the mean (it has a negative sign). The standard normal tables does not have these values. However, we can find them subtracting the value of the probability obtained for z = 1.16 from 1, since the symmetry for normal distribution permits it. Then, the probability associated with z = -1.16 is:

$\\ P(z$

Then, the probability that a hotel room costs less than $140 per night is P(x<$140) = 0.1230 or 12.30%.

<h3>What is the probability that a hotel room costs between $200 and $300 per night?</h3>

$\\ z_{score}=\frac{x-\mu}{\sigma}$

<em>The z-score and probability for x = $200:</em>

$\\ z_{score}=\frac{200-204}{55}$

$\\ z_{score}= -0.072727 \approx -0.07$

$\\ P(z$

<em>The z-score and probability for x = $300:</em>

$\\ z_{score}=\frac{300-204}{55}$

$\\ z_{score}=1.745454$

$\\ P(z$

Then, the probability that a hotel room costs between $200 and $300 per night is 0.48784 or 48.78%.

<h3>What is the cost of the most expensive 20% of hotel rooms in New York City?</h3>

A way to solve this is as follows: we need to consult, using the cumulative standard normal table, the value for z such as the probability is 80%. This value is, approximately, z = 0.84. Then, solving the next equation for <em>x:</em>

$\\ z_{score}=\frac{x-\mu}{\sigma}$

$\\ 0.84=\frac{x-204}{55}$

$\\ 0.84*55=x-204$

$\\ 0.84*55 + 204 =x$

$\\ x = 250.2$

That is, the cost of the most expensive 20% of hotel rooms in New York City are of $250.20 or more.

6 0

3 years ago