All categories

3 years ago

Kelly found the area of the composite figure below and showed her work on a quiz. Her teacher marked her answer incorrect.

Mathematics

1 answer:

Stella [2.4K]3 years ago

6 0

Answer:

446.75 y^2

Step-by-step explanation:

First, Kelly found the area of a circle, not half a circle, which is on top of the figure. She also shouldn't have subtracted the area of the circle by the airea of the base, as she is trying to find the area of the ENTIRE figure.

.5 TIMES pi times 9^2 = 122.75

the second part, calculating the square base is correct..

122.75+324 = 446.75 y^2

You might be interested in

Hello,

Nookie1986 [14]

Answer:

s = height above ground

s = 60 + 20 t - 4.9 t^2 (standard physics equation on earth)

at t = 0

s = 60 (clearly :)

now when does it hit the bleak earth?

That is when s = 0

4.9 t^2 - 20 t -60 = 0

solve quadratic and use the positive t (the negative t was back before you threw it if you had thrown it from the ground)

t = 6.09 or - 2.01

use t = 6.09

now to do the last part there are two obvious ways to get t at the peak

1. look for vertex of parabola

2. look for halfway between t = -2.01 and t = 6.09

I will do it the hard (11) waay by completing the square

4.9 t^2 - 20 t = -(s-60)

t^2 - 4.08 t = -.204 s + 12.2

t^2 - 4.08 t +2.04^2 = -.204 s +12.2 + 4.16

(t-2.04)^2 = -.204(s-80.2)

top at 80.2 meters at t = 2.04 s

===============

quick check on time

should be average of 6.09 and -2.01

=4.08 /2 = 2.04 check

7 0

2 years ago

Read 2 more answers

A random sample of 40 college students has a mean earnings of $3120 over the summer months. Assume the population standard devi

PSYCHO15rus [73]

Answer:

A normal distribution or z-test is used to construct a confidence interval.

Step-by-step explanation:

We are given the following in the question:

Sample mean, $\bar{x}$ = $3120

Sample size, n = 40

Population standard deviation, σ = $677

The distribution of earnings of college is a normal distribution.

Conditions:

Since we are given the population standard deviation and the the sample size is also greater than 30.

Conclusion:

Thus, we use a normal distribution or z-test to construct a confidence interval.

4 0

4 years ago

48, 56, 68, 72, 72, 78, 78, 80, 82, 84, 88, 88, 88, 90, 94, 98, 100

agasfer [191]

Answer:

Step-by-step explanation:

Range is the largest value minus the smallest value

100 - 48 = 52

8 0

3 years ago

Read 2 more answers

Tripp and Rico are two dogs. Tripp weighs exactly 35 pounds more than Rico. Together, they weigh exactly 49 pounds. How much doe

babymother [125]

Call the weights of the two dogs $t$ and $r$ .

We know that Tripp weights 35lbs more than Rico, or:
$t=r+35$

We also know that the total weight of both dogs is 49lbs.:
$t+r=49$

Now, by substitution:
$(r+35)+r=49$
$2r+35=49$
$2r+35-35=49-35$
$2r=14$
$r=\frac{14}{2}$
$r=7$
Rico weighs 7lbs.

Then:
$t=r+35$
$t=7+35$
$t=42$
Tripp weighs 42lbs.

To check our work:
$t+r=49$
$42+7=49$
$49=49$ CHECK!

5 0

3 years ago

Which of the binomials below is a factor or this trinomial x-2 +5x+6

lutik1710 [3]

Firstly, for it to be a trinomial the expression would have to be x^2+5x+6 to factor this we would simply have to find 2 numbers that add up to 5 and multiply to 6. 3+2=5 and 3•2=6 so (x+3)(x+2) would be the answer

5 0

3 years ago