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Artyom0805 [142]
4 years ago
11

A ball is thrown in the air from a ledge. It's height in feet represented by f(x)=16(x^2-6x-7), where x is the number of seconds

since the ball has been thrown. The height of the ball is 0 feet when it hits the ground. How many seconds does it take the ball to reach the ground?
Mathematics
2 answers:
LekaFEV [45]4 years ago
7 0

Answer:

Step-by-step explanation:

Since we know that the height is 0, we can figure out how long it took the ball to reach the ground by setting f(x) = 0 and solving for x:

f(x) = 16(x^{2} - 6x - 7)

0 = 16(x^{2} - 6x - 7)

0 = x^{2} - 6x - 7

0 = (x - 7)(x + 1)

x = -1, 7

Because time can only be positive, the answer is 7 seconds.

lutik1710 [3]4 years ago
4 0

Answer:

7 seconds.

Step-by-step explanation:

height h = 16(x^2-6x-7) = 0

x^2 - 6x - 7 = 0

(x - 7)(x + 1) = 0

x = 7 seconds (we ignore the negative).

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Some parts of California are particularly earthquake-prone.
Lyrx [107]

Answer:

a) P(X=0)=(4C0)(0.27)^0 (1-0.27)^{4-0}=0.283982

P(X=1)=(4C1)(0.27)^4 (1-0.27)^{4-1}=0.420138

P(X=2)=(4C2)(0.27)^5 (1-0.27)^{4-2}=0.23309

P(X=3)=(4C3)(0.27)^3 (1-0.27)^{4-3}=0.057474

P(X=4)=(4C4)(0.27)^4 (1-0.27)^{4-4}=0.05314

b) For this case the value with the higher probability is X=1, so then would be the most likely value.

c) P(X \leq 1) = P(X=0) +P(X=1) = 0.283982+0.420138=0.704121 \approx 0.7041

d) P(X \leq 2) =1-{(X

e) For this case the expected value is given by:

E(X) = \mu = np= 4*0.27= 1.08

The variance is given by:

\sigma^2 = Var(X) = np(1-p) =4*0.27*(1-0.27)= 0.7884

And the deviation is:

Sd(X) = \sigma = \sqrt{0.7884}=0.89

Step-by-step explanation:

Previous concepts

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

Solution to the problem

Let X the random variable of interest, on this case we now that:

X \sim Binom(n=4, p=0.27)

The probability mass function for the Binomial distribution is given as:

P(X)=(nCx)(p)^x (1-p)^{n-x}

Where (nCx) means combinatory and it's given by this formula:

nCx=\frac{n!}{(n-x)! x!}

Part a

P(X=0)=(4C0)(0.27)^0 (1-0.27)^{4-0}=0.283982

P(X=1)=(4C1)(0.27)^4 (1-0.27)^{4-1}=0.420138

P(X=2)=(4C2)(0.27)^5 (1-0.27)^{4-2}=0.23309

P(X=3)=(4C3)(0.27)^3 (1-0.27)^{4-3}=0.057474

P(X=4)=(4C4)(0.27)^4 (1-0.27)^{4-4}=0.05314

Part b

For this case the value with the higher probability is X=1, so then would be the most likely value.

Part c

For this case we want this probability:

P(X \leq 1)

And we can find this probability like this:

P(X \leq 1) = P(X=0) +P(X=1) = 0.283982+0.420138=0.704121 \approx 0.7041

Part d

For this case we want this probability:

P(X \leq 2)

And we can find this probability using the complement rule like this:

P(X \leq 2) =1-{(X

Part e

For this case the expected value is given by:

E(X) = \mu = np= 4*0.27= 1.08

The variance is given by:

\sigma^2 = Var(X) = np(1-p) =4*0.27*(1-0.27)= 0.7884

And the deviation is:

Sd(X) = \sigma = \sqrt{0.7884}=0.89

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3 years ago
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JulsSmile [24]
The answer to your answer is 220 after evaluating this expression. Hope i helped out.
6 0
4 years ago
Read 2 more answers
I got x = 45 <br> And I was wondering if anyone one could tell me if im correct
slamgirl [31]

Answer:

<em>x = 45°</em>

Step-by-step explanation:

<u>Congruence of Angles:</u>

Linear angles are those consecutive angles formed when two lines cross. Their sum of linear angles is 180°.

Corresponding angles are those which occupy the same relative position at each intersection where a straight line crosses two others. If the two lines are parallel, the corresponding angles are congruent.

From the provided figure, angles y and 3x-60 are linear, thus:

y + 3x - 60 = 180

y = 180 - 3x + 60

y = 240 - 3x

Also, being p and q parallel lines, angles y and 2x+15 are corresponding, thus:

240 - 3x = 2x + 15

Adding 3x:

240 = 2x + 3x + 15 = 5x + 15

Subtracting 15:

240 - 15 =5x = 225

Dividing by 5:

x = 225 / 5 = 45

x = 45°

3 0
3 years ago
Solve 4(2x-3)+4=8x-8
IrinaK [193]

Answer:

- 84

Step-by-step explanation:

4 (2x-3)+4=-20.

8x-8=-64

-20+-64=-84

6 0
4 years ago
Read 2 more answers
What is the square root of 81
motikmotik

Answer:

9

Step-by-step explanation:

7 0
3 years ago
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