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julia-pushkina [17]

3 years ago

6

The altitude of an airplane is decreasing at a rate of 40 feet per second. What is the change in altitude of the airplane over a

period of 20 seconds?

1 answer:

Alexxx [7]3 years ago

4 0

Answer:

Step-by-step explanation:

-40t

-40(20)

-800 ft

You might be interested in

The population of lengths of aluminum-coated steel sheets is normally distributed with a mean of 30.05 inches and a standard dev

Vladimir [108]

Answer:

Probability that the average length of a sheet is between 30.25 and 30.35 inches long is 0.0214 .

Step-by-step explanation:

We are given that the population of lengths of aluminum-coated steel sheets is normally distributed with a mean of 30.05 inches and a standard deviation of 0.2 inches.

Also, a sample of four metal sheets is randomly selected from a batch.

Let X bar = Average length of a sheet

The z score probability distribution for average length is given by;

Z = $\frac{Xbar-\mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, $\mu$ = population mean = 30.05 inches

$\sigma$ = standard deviation = 0.2 inches

n = sample of sheets = 4

So, Probability that average length of a sheet is between 30.25 and 30.35 inches long is given by = P(30.25 inches < X bar < 30.35 inches)

P(30.25 inches < X bar < 30.35 inches) = P(X bar < 30.35) - P(X bar <= 30.25)

P(X bar < 30.35) = P( $\frac{Xbar-\mu}{\frac{\sigma}{\sqrt{n} } }$ < $\frac{30.35-30.05}{\frac{0.2}{\sqrt{4} } }$ ) = P(Z < 3) = 0.99865

P(X bar <= 30.25) = P( $\frac{Xbar-\mu}{\frac{\sigma}{\sqrt{n} } }$ <= $\frac{30.25-30.05}{\frac{0.2}{\sqrt{4} } }$ ) = P(Z <= 2) = 0.97725

Therefore, P(30.25 inches < X bar < 30.35 inches) = 0.99865 - 0.97725

= 0.0214

7 0

3 years ago

Please answer this and will marked as brainlist

xeze [42]

<h3>Answer: 1</h3>

where x is nonzero

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

Explanation:

We'll use two rules here

(a^b)^c = a^(b*c) ... multiply exponents
a^b*a^c = a^(b+c) ... add exponents

------------------------------

The portion [ x^(a-b) ]^(a+b) would turn into x^[ (a-b)(a+b) ] after using the first rule shown above. That turns into x^(a^2 - b^2) after using the difference of squares rule.

Similarly, the second portion turns into x^(b^2-c^2) and the third part becomes x^(c^2-a^2)

-------------------------------

After applying rule 1 to each of the three pieces, we will have 3 bases of x with the exponents of (a^2-b^2), (b^2-c^2) and (c^2-a^2)

Add up those exponents (using rule 2 above) and we get

(a^2-b^2)+(b^2-c^2)+(c^2-a^2)

a^2-b^2+b^2-c^2+c^2-a^2

(a^2-a^2) + (-b^2+b^2) + (-c^2+c^2)

0a^2 + 0b^2 + 0c^2

0+0+0

0

All three exponents add to 0. As long as x is nonzero, then x^0 = 1

4 0

3 years ago

CORRECT ANSWER GETS BRAINLIEST A frequency table of grades has five classes (A, B, C, D, F) with frequencies of 4,11 ,15 ,

ra1l [238]

Answer:

A = 10.5%

B = 28.9%

C = 39.5%

D = 18.4%

F = 2.6%

Step-by-step explanation:

Add all the frequencies together = 38

4/38 × 100 = 10.5%
11/38 × 100 = 28.9%
15/38 × 100 = 39.5%
7/38 × 100 = 18.4%
1/38 × 100 = 2.6%

10.5 + 28.9 + 39.5 + 18.4 + 2.6 = 100%

5 0

3 years ago

This is the other question!

joja [24]

I’m not 100% true but i think it’s false, true, true :)

6 0

2 years ago

Read 2 more answers

An elevator can hold a maximum of 1500 pounds. An average child weighs 75 pounds and the average adult weighs 150 pounds. The el

CaHeK987 [17]

<u>Let's take this problem step-by-step</u>:

<u>Let's first set up some variables</u>:

c: # of children
a: # of adults

<u>Let's examine the information given:</u>

Elevator can hold a maximum of 1500 pounds

⇒ average child is 75 pounds

⇒ average adult is 150 pounds

⇒<em> therefore</em>: $75c + 150a\leq 1500$

Elevator can fit no more than 14 people

⇒ <em>therefore</em>: $c + a \leq 14$

<u>Let's graph the equations</u>:

$75c+150a\leq 1500\\c+a\leq 14$

⇒ look at the image attached

<u>The point at which the two graphs intersect:</u>

⇒ <em>is the solution that represents the amount of children and adults and </em>

<em> their combine weight</em>

<em />

<u><em>With the horizontal axis being the # of children and vertical axis being the # of adults</em></u><em>:</em>

<em> ⇒ the </em><em>solution is 8 children and 6 adults</em>

<em></em>

<u>Answer: 8 children and 6 adults</u>

<u></u>

Hope that helped!

<em />

7 0

2 years ago