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2 years ago

A top swimmer would be able to swim across a 25-meter pool in about 1/5

Mathematics

1 answer:

Anni [7]2 years ago

7 0

Answer:

125 m/min

Step-by-step explanation:

Find the rate (speed) as follows:

25 meters

--------------------- = (125/1) meters/min = 125 m/min

(1/5) minute

This is equivalent to about 380 ft/min

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2 years ago

Give an example of a system of linear equations that can be solved by first adding the equations to eliminate one variable.

telo118 [61]

f ( 7 ) = 2.4 ft

Step-by-step explanation:

Solution:-

- This is modeled using a geometric sequence function with initial height from which ball is dropped hi = 18 feet, and a decrease in height by 25% after each successive bounce :

f ( x ) = 18 (0.75)^x

Where, x e [ 0 , ∞ ) : The number of bounces.

f (x) : The maximum height after xth bounce.

- The maximum height reached by the ball after its 7th bounce. So, x = 7:

f ( 7 ) = 18 (0.75)^7

f ( 7 ) = 2.4027 ft

- To the nearest tenth:

f ( 7 ) = 2.4 ft

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2 years ago

The length of a rectangle is three inches more than the width. the area of the rectangle is 180 inches. find the width of the re

ch4aika [34]

We have a rectangle with length L that is 3 inches more than the width W. Then we can write this as:

$L=W+3$

The area of the rectangle is 180 square inches.

We have to find the width W.

As the area is equal to the product of the length and the width, we can write this equation and solve for W as:

$\begin{gathered} A=180 \\ L\cdot W=180 \\ (W+3)\cdot W=180 \\ W^2+3W=180 \\ W^2+3W-180=0 \end{gathered}$

We have a quadratic equation. The roots of this equation will be the mathematical solutions.

We can find the roots using the quadratic formula:

$\begin{gathered} W=\frac{-b\pm\sqrt[]{b^2-4ac}}{2a} \\ W=\frac{-3\pm\sqrt[]{3^2-4\cdot1\cdot(-180)}}{2\cdot1} \\ W=\frac{-3\pm\sqrt[]{9+720}}{2} \\ W=\frac{-3\pm\sqrt[]{729}}{2} \\ W=\frac{-3\pm27}{2} \\ W_1=\frac{-3-27}{2}=-\frac{30}{2}=-15 \\ W_2=\frac{-3+27}{2}=\frac{24}{2}=12 \end{gathered}$

The solutions are W = -15 and W = 12.

The first one is not valid, as W has to be greater than 0.

Then, the solution to our problem is W = 12 in.

Answer: the width is W = 12 inches.

6 0

8 months ago

hey guys! please give an easy explanation on how to do this once you find the answer so I can try doing it myself! thank you :)

Svet_ta [14]

Answer:

i think its d :both a and b

Step-by-step explanation:

i think

5 0

2 years ago

We intend to estimate the average break time of Dunder Mifflin employees. From a previous study, we believe that the average tim

arsen [322]

Answer:

The minimum sample size that we should consider is of 60 employees.

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1-0.99}{2} = 0.005$

Now, we have to find z in the Ztable as such z has a pvalue of $1-\alpha$ .

So it is z with a pvalue of $1-0.005 = 0.995$ , so $z = 2.575$

Now, find the margin of error M as such

$M = z*\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

We want our 99 percent confidence interval to have a margin of error of no more than plus or minus 2 minutes. What is the smallest sample size that we should consider?

We need to find n for which $M = 2, \sigma = 6$