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2 years ago

13

If you take a number times by 3 then add 5 you get the same as if you took the number times by 7 then subtract 8 what is the num

ber

1 answer:

Furkat [3]2 years ago

8 0

Answer:

3 1/4

Step-by-step explanation:

3x+5=7x-8

Subtract 5 from both sides

3x=7x-13

Subtract 7 from both sides

-4x= -13

Divide by -4

X= 13/4

SIMPLIFIED: 3 1/4

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A rope is tied to the bottom of a hot air balloon as shown below. The rope makes an angle of 35 degrees with the ground distant

Serjik [45]

We have a right triangle. We know the hypotenuse (75 ft) and an angle of 35°. We need to find the opposite leg to the angle of 35° (h). The trigonometric function that relates the opposite leg to an angle with the hypotenuse is sine:
sin 35° = (Opposite leg to 35°) / hypotenuse
sin 35° = h/(75 ft)

Solving for h:
(75 ft) sin 35°=h
h=75 sin 35° ft
h=75 (0.573576436) ft
h=43.01823270 ft
h=43 ft

Answer: T<span>he bottom of the balloon is 43 ft from the ground</span>

8 0

3 years ago

The diameter of a circle is 16 meters what is the area

KengaRu [80]

Answer:

201.1 meters squared

Step-by-step explanation:

A= pi*r squared

Diameter= 16, to find the radius we must divide by 2

16/2=8

Radius= 8

A= pi* (8)^2

A= 201.06

The area of the circle is 201.1 meters squared.

3 0

3 years ago

5 times marys age is the same as 28 less than 7 times her age. Find her age

Gnom [1K]

setup a simple algebraic equation and solve.

5x = 7x-28

-5x -5x

0=2x-28

+28 +28

28=2x

Now divide both sides by 2 and you get that she is 14

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3 years ago

Read 2 more answers

Help! please answer ASAP!

ValentinkaMS [17]

The answer would be 7,6,5,4,3,2,1 inches tall in the chronological order

5 0

3 years ago

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According to a Yale program on climate change communication survey, 71% of Americans think global warming is happening.† (a) For

SpyIntel [72]

Answer:

a) 0.2741 = 27.41% probability that at least 13 believe global warming is occurring

b) 0.7611 = 76.11% probability that at least 110 believe global warming is occurring

Step-by-step explanation:

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

The expected value of the binomial distribution is:

$E(X) = np$

The standard deviation of the binomial distribution is:

$\sqrt{V(X)} = \sqrt{np(1-p)}$

Normal probability distribution

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

When we are approximating a binomial distribution to a normal one, we have that $\mu = E(X)$ , $\sigma = \sqrt{V(X)}$ .

In this problem, we have that:

$p = 0.71$

(a) For a sample of 16 Americans, what is the probability that at least 13 believe global warming is occurring?

Here $n = 16$ , we want $P(X \geq 13)$ . So

$P(X \geq 13) = P(X = 13) + P(X = 14) + P(X = 15) + P(X = 16)$

In which

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 13) = C_{16,13}.(0.71)^{13}.(0.29)^{3} = 0.1591$

$P(X = 14) = C_{16,14}.(0.71)^{14}.(0.29)^{2} = 0.0835$

$P(X = 15) = C_{16,15}.(0.71)^{15}.(0.29)^{1} = 0.0273$

$P(X = 16) = C_{16,16}.(0.71)^{16}.(0.29)^{0} = 0.0042$

$P(X \geq 13) = P(X = 13) + P(X = 14) + P(X = 15) + P(X = 16) = 0.1591 + 0.0835 + 0.0273 + 0.0042 = 0.2741$

0.2741 = 27.41% probability that at least 13 believe global warming is occurring

(b) For a sample of 160 Americans, what is the probability that at least 110 believe global warming is occurring?

Now $n = 160$ . So

$\mu = E(X) = np = 160*0.71 = 113.6$

$\sigma = \sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{160*0.71*0.29} = 5.74$

Using continuity correction, this is $P(X \geq 110 - 0.5) = P(X \geq 109.5)$ , which is 1 subtracted by the pvalue of Z when X = 109.5. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{109.5 - 113.6}{5.74}$

$Z = -0.71$

$Z = -0.71$ has a pvalue of 0.2389

1 - 0.2389 = 0.7611

0.7611 = 76.11% probability that at least 110 believe global warming is occurring

3 0

3 years ago