Only 6 of the 75 trees in a park are at least 30 feet tall. What percent of the trees are under 30 feet tall?

The area of a circle is 1441 m2.<br> What is the diameter of the circle?

gregori [183]

Hey there! I'm happy to help!

The area of a circle is the radius squared multiplied by pi (we will use 3.14). We already have the area, so we will go backwards.

1441÷3.14≈458.9171975

We find the square root.

√458.9≈21.42235275

Now we have our approximate radius. The diameter is twice the radius.

21.42235275×2=42.8447055

I don't know exactly if they want you to round it or not, but the diameter is somewhere around there.

Have a wonderful day! :D

6 0

3 years ago

An average score of 90 or above in an English course receives an A grade. A student has grades of 81, 87, 94, 93 on four tests.

Inessa05 [86]

Answer:

95>=X <=100. More or equal to 95 or equal or less than 100.

Step-by-step explanation:

The Total of the first score is needed first

81+87+ 94+93=355

The total of this score

Let X be the 5TH score we are looking for

(355+ X)/5= 90

355+X= 450

X= 450-355

X= 95 the person needs to sore between 95 and 100 ( which is the highest possible score).

5 0

3 years ago

Duffy was analyzing the trajectory made after throwing a football. his coach was able to measure that his throw reached a maximu

gregori [183]

Answer:

4.35 seconds.

Step-by-step explanation:

Let x represent the time the independent variable and y be dependent variable (height of the ball).

We are told that Duffy figured that the ball left his hand at a height of 5 feet. This means at x equals 0, y was 5 or initial height of ball is 5 feet.

We have been given that Duffy's coach measured that his throw reached a maximum height of 18 feet after 2 seconds. This means that at x equals 2 y was 18.

As point (2,18) represents maximum height of ball, so it will be vertex of parabola.

Since initial height of ball is less than maximum height, so our parabola will be downward opening and leading coefficient will be negative.

We know that vertex form of a downward opening parabola is in form: $y=-a(x-h)^2+k$

$y=-a(x-2)^2+18$

Let us find value of a using point (0,5).

$5=-a(0-2)^2+18$

$5=-a*4+18$

$5-18=-a*4+18-18$

$-13=-4a$

$\frac{-13}{-4}=\frac{-4a}{-4}$

$\frac{13}{4}=a$

Therefore, the equation $y=-(\frac{13}{4})(x-2)^2+18$ can be used to find the height of ball after x seconds.

To find the time it will take the ball to hit the ground, we will substitute y equals 0 in our equation.

$0=-(\frac{13}{4})(x-2)^2+18$

$0-18=-(\frac{13}{4})(x-2)^2+18-18$

$0-18=-(\frac{13}{4})(x-2)^2$

$-18*(\frac{4}{13})=-(x-2)^2$

$\frac{72}{13}=(x-2)^2$

Taking square root of both sides of our equation we will get,

$\sqrt{\frac{72}{13}}=x-2$

$x-2\pm 2.35339$

$x-2=2.35339\text{ (or) } x-2=2.35339$

$x-2+2=2.35339+2\text{ (or) } x-2+2=-2.35339+2$

$x=4.35339\text{ (or) } x=-0.35339$

$x\approx 4.35\text{ (or) } x\approx -0.35$

Since time can not be negative, therefore, the ball will hit the ground approximately after 4.35 seconds.

7 0

3 years ago

For number 6 can anyone tell me the answer

slamgirl [31]

The perimeter of MATH is 4w + 6 and the perimeter of GEOM is 6w - 8. the perimeters are the same so set them equal,
4w + 6 = 6w - 8... use inverse to get all like terms on opposite sides
-4w + 8 = -4w + 8
14 = 2w... divide both side by 2 to get w alone
÷2 = ÷2
7 = w
so B. 7 is the answer

7 0

3 years ago

Niko spent $23.25 a raffle ticket that cost $.75 each which of the following is the number of raffle tickets nickel bought

miskamm [114]

Answer:

31 raffle tickets

Step-by-step explanation:

23.25 divided by 0.75 = 31

8 0

2 years ago

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