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2 years ago

To the nearest tenth, what is the area of a circle whose diameter is 4.4 feet?

Mathematics

2 answers:

Vaselesa [24]2 years ago

6 0

Answer:

15.21= 15.2 when rounded

Step-by-step explanation:

the formula for finding the area of a circle with the diameter is
A= 1/4 × π ×d^2

Aneli [31]2 years ago

5 0

Answer:

15.21

Step-by-step explanation:

In order to find the area, you must find the radius first.

The diameter (4.4) divided by 2 = radius (2.2)

The area of a circle is pi times the radius squared ( $A = \pi r^{2}$ ).

In this situation, r, or radius =2.2.

$A = \pi 2.2^{2}$

$\pi$ $2.2^{2}$ = the area, 15.2053084434.

By rounding to the nearest hundredth, you get 15.21. The second number after the decimal is your hundredths place. If the number after the decimal is 4 or less, just remove all of the digits to the right. If it's five or more, like this case where it is 7, you add 1 to the hundredths place, then you remove all of the digits to the right.

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Betsy caught three fish. The weights of the fish were 3 lb 2 oz, 2 lb 11 oz, and 2 lb 8 oz. What was the total weight of the thr

UkoKoshka [18]

Answer:

8 lbs 5 oz

Step-by-step explanation:

When you add 3 lbs, 2 lbs, and 2 lbs you get 7 lbs.

There are 16 oz in a lb. When you add the number of oz you get 21 oz which is the same as 1 lb and 5 oz.

you then add 7 lbs to 1 lb and 5 oz and get 8 lbs and 5 oz.

5 0

3 years ago

Find the discriminant and the number of real roots for this equation. x^2 + 2x + 8 = 0

ehidna [41]

Step-by-step explanation:

A is correct option there are no real roots

because discriminant is less than zero

5 0

3 years ago

Solve for a please show all your work

o-na [289]

Z = -b - a + 1

subtract 1
1z - 1 = -1b - 1a ( 1z is the same as z, same goes for b and a)

add -1b
1b - 1z - 1 = -1a

then we remove -1 by dividing it.
-1b -(-1z) + 1

Answer: -1b -(-1z) + 1 = A

A negative minus a negative is a positive, so the answer might as well be....
-1b + 1z + 1 = A

6 0

3 years ago

Use the Law of Cosines to find angle round to the nearest tenth if necessary).

ad-work [718]

Answer:

Step-by-step explanation:

3a)

find side HP , let's set side HP = c in the law of cosines formula

then

c = sq rt [ 23^2 + 12^2 - 2*12*23*cos(117) ]

c = sq rt [ 529 + 144 - (-250.6027559) ]

c = sq rt [ 673 + 250.6027559 ]

c = sq rt [ 923.602755 ]

c = 30.39

then

HP = 30.4 ( rounded to nearest 10th )

3b)

let PR = c, then law of cosines is (we need angle Q also 180=24+97+Q is 59°

c = sq rt [ 9^2 + 22^2 - 2*9*22*cos(59) ]

c = sq rt [ 81 + 484 -396*0.5150380 ]

c = sq rt [ 565 - 203.955 ]

c = sq rt [ 391.04495]

c = 19.7748

PR = 19.8 ( rounded to nearest 10th )

3c)

they want us to find ∠B, in the formula for cosines ∠B is really ∠C, it's a bit confusing.. I'm sure they did that on purpose to mess people up. Kind of underhanded :/ Tell the teacher that you're "appalled" at the deviousness of the test :/ stage a protest against math that teaches treachery :P storm the principals/ dean's office with paper airplanes and pictures of anime :DDD okay back to math.

a=28

b=17

c=15

since we want angle B then the formula looks like

B= arcCos ( a^2 + c^2 - b^2 / 2*a*c) so we'll avoid messing up the which side is which ... by setting up the formula this way .. got it?

B = arcCos [28^2 + 15^2 - 17^2 / 2*28*15]

B = arcCos[784 + 225 - 289 /840 ]

B = arcCos[720/ 840]

B = arcCos[0.85714285]

B = 31.0027 °

that it came out so close to an integer I'm pretty sure it's right

∠B = 31 .0 ° ( rounded to the nearest 10th )

3d)

find ∠A

set it up carefully again, they are asking us to move the variable around again

a = 18

b= 28

c= 12

then the formula looks like

∠A = arcCos[ b^2 + c^23 - a^2 / 2*b*c ]

∠A = arcCos[28^2 + 12^2 - 18^2 /2*28*12 ]

∠A = arcCos[784 + 144 -324 / 672 ]

∠A = arcCos[604/672]

∠A = arcCos[0.8988095]

∠A =25.99797 °

∠A =26.0 ° ( rounded to nearest 10th)

7 0

3 years ago

What is the significance of the mean of a probability distribution?

VikaD [51]

Answer:

Significance of the mean of a probability distribution.

Step-by-step explanation:

The mean of a probability distribution is the arithmetic average value of a random variable having that distribution.

For a discrete probability distribution, the mean is given by, $\sum x_iP(x_i)$ , where P(x) is the probabiliy mass function.
For a continuous probability distribution, the mean s given by, $E(x) = \int x_if(x_i)$ , where f(x) is the probability density function.
Mean is a measure of central location of a random variable.
It is the weighted average of the values that X can take, with weights given by the probability density function.
The mean is known as expected value or expectation of X.
An important consequence of this is that the mean of any symmetric random variable (continuous or discrete) is always on the axis of symmetry of the distribution.
For a continuous random variable, the mean is always on the axis of symmetry of the probability density function.

4 0

3 years ago