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2 years ago

20 pounds to 16 pounds is what present

Mathematics

2 answers:

suter [353]2 years ago

7 0

The answer is twenty percent

ExtremeBDS [4]2 years ago

6 0

Answer:

Decreased by 20%.

16 lbs is 80% of 20 lbs.

Step-by-step explanation:

$\frac{y}{100} :\frac{16}{20}$

y × 20 = 16 × 100

20y = 1600

20y ÷ 20 = 1600 ÷ 20

y = 80

100% - 80% = 20%

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4 x (2 x 7) = (4 x 2) x ___

natka813 [3]

Answer:

x=0

Step-by-step explanation:

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3 years ago

At the U.S open tennis championship a statistician keeps track of every serve that a player hits during the tournament. The mean

GarryVolchara [31]

Answer:

Step-by-step explanation:

Both 115 and 145 mph are above the mean. Draw a normal curve and mark these speeds. 115 mph is 1 standard deviation above the mean; 130 would be 2 standard deviations above the mean; and 145 would be 3 s. d. above it.

We need to find the area under the standard normal curve between 115 and 145. This is equivalent to the area under the standard normal curve between z = 1 and z = 3.

I used my TI-83 Plus calculator's DISTR function "normalcdf(" to calculate this area: normalcdf(1, 3) = 0.1573.

The area between z = 1 and z = 3 is 0.1573. In other words, the percentage of serves that were between 115 and 145 mph was 15.73%.

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2 years ago

A hypothetical square grows so that the length of its diagonals are increasing at a rate of 8m/min. How fast is the area of the

ad-work [718]

Answer: The area of the square is increasing at a rate of 90.4 m2/min (square meters/minute)

Step-by-step explanation: Please see the attachments below

7 0

3 years ago

Read 2 more answers

5. An airplane takes 4 hr to travel a distance of 4100 km. Another airplane travels at a speed

Mazyrski [523]

Answer:

4.969696 hours

Step-by-step explanation:

The distance traveled is shown through the following equations

Distance = velocity * time

This means that

4100=velocity*4

This means that ariplane 1 travles at 1025 km/hr

We can then subtract 200 from this to find that airplane two travels at a speed of 825 km/hr

Now we need to find how long it takes for that plane to travel 4100

So using the same equation

4100=825*time

Divison will tell us that the answer is around 4.9696 hours which is pretty much 5

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3 years ago

Terri Vogel, an amateur motorcycle racer, averages 129.71 seconds per 2.5 mile lap (in a 7 lap race) with a standard deviation o

Vikki [24]

Answer:

(a) The percent of her laps that are completed in less than 130 seconds is 55%.

(b) The fastest 3% of her laps are under 125.42 seconds.

Step-by-step explanation:

The random variable X is defined as the number of seconds for a randomly selected lap.

The random variable X is normally distributed with mean, μ = 129.71 seconds and standard deviation, σ = 2.28 seconds.

Thus, $X\sim N(129.71,\ 2.28^{2})$ .

(a)

Compute the probability that a lap is completes in less than 130 seconds as follows:

$P(X$

$=P(Z$

The percentage is, 0.55 × 100 = 55%.

Thus, the percent of her laps that are completed in less than 130 seconds is 55%.

(b)

Let x represents the 3rd percentile.

That is, P (X < x) = 0.03.

⇒ P (Z < z) = 0.03

The value of z for the above probability is:

z = -1.88

Compute the value of x as follows:

$z=\frac{x-\mu}{\sigma}\\-1.88=\frac{x-129.71}{2.28}\\x=129.71-(1.88\times 2.28)\\x=125.4236\\x\approx 125.42$

Thus, the fastest 3% of her laps are under 125.42 seconds.

(c)

Let x₁ and x₂ be the values between which the middle 80% of the distribution lie.

That is,

$P(x_{1}$

The value of z for the above probability is:

z = 1.28

Compute the values of x₁ and x₂ as follows:

$-z=\frac{x_{1}-\mu}{\sigma}\\-1.28=\frac{x_{1}-129.71}{2.28}\\x_{1}=129.71-(1.28\times 2.28)\\x=126.7916\\x\approx 126.80$ $z=\frac{x_{2}-\mu}{\sigma}\\1.28=\frac{x_{2}-129.71}{2.28}\\x_{2}=129.71+(1.28\times 2.28)\\x=132.6284\\x\approx 132.63$

Thus, the middle 80% of her laps are from 126.80 seconds to 132.63 seconds.

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3 years ago