What is 7 x 7 x 7 written using an exponent?

A sewer line drops 1 foot every 40 feet. How many feet will it drop over a distance of 100 feet

kodGreya [7K]

Answer:

2.5

Step-by-step explanation:

3 0

3 years ago

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A commuter must pass through 5 traffic lights on her way to work and will have to stop at each one that is red. She estimates th

sergij07 [2.7K]

Answer:

(a) The mean or expected value of X is 2.2.

(b) The standard deviation of X is 1.3.

Step-by-step explanation:

Let X = number of times the traffic light is red when a commuter passes through the traffic lights.

The probability distribution of X id provided.

The formula to compute the mean or expected value of X is:

$\mu=E(X)=\sum x.P(X=x)$

The formula to compute the standard deviation of X is:

$\sigma=\sqrt{E(X^{2})-(E(X))^{2}}$

The formula of E (X²) is:

$E(X^{2})=\sum x^{2}.P(X=x)$

(a)

Compute the expected value of X as follows:

$E(X)=\sum x.P(X=x)\\=(0\times0.06)+(1\times0.25)+(2\times0.35)+(3\times0.15)+(4\times0.13)+(5\times0.06)\\=2.22\\\approx2.2$

Thus, the mean or expected value of X is 2.2.

(b)

Compute the value of E (X²) as follows:

$E(X^{2})=\sum x^{2}.P(X=x)\\=(0^{2}\times0.06)+(1^{2}\times0.25)+(2^{2}\times0.35)+(3^{2}\times0.15)+(4^{2}\times0.13)+(5^{2}\times0.06)\\=6.58$

Compute the standard deviation of X as follows:

$\sigma=\sqrt{E(X^{2})-(E(X))^{2}}\\=\sqrt{6.58-(2.22)^{2}}\\=\sqrt{1.6516}\\=1.285\\\approx1.3$

Thus, the standard deviation of X is 1.3.

4 0

4 years ago

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(15 POINTS!) The graph shows the distance a ghost crab can run over time the D equals the distance in meters and the t equal the

Maru [420]

Answer:

B. d = 5/3t

Step-by-step explanation:

The complete question is shown in the figure attached with.

We need to find the equation of direct variation using the graph. The general equation for a direction variation is:

y = kx

In this case, the variable along x axis is time in seconds i.e. "t" and the variable along y axis is distance in meters i.e. "d". So, the equation for this case would be:

d = kt

We need to find the value of "k" to complete this equation. For this we can use any point from the graph and substitute it in the above equation. From the graph we can see that the distance covered for time = 3 seconds is 5 meters. Substituting t =3 and d = 5 in above equation, we get:

5 = 3k

k = 5/3

Using the value of k in the above equation, we get:

$d=\frac{5}{3}t$

Therefore, option B gives the correct answer

7 0

3 years ago

Why is 3/8 bigger than 3/12

Stolb23 [73]

Answer:

3/ 8 is greater than 3/ 12 because if you cross multiply 12 times 3 is 36 and 3 times 8 is 24

Step-by-step explanation:

4 0

2 years ago

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Sonja's house is 4 blocks west and 1 block south of the center of town. Her school is 3 blocks east and 2 blocks north of the ce

dexar [7]

If the center of town is the origin then 4 blocks west and 1 block south would be 4 blocks to the left and 1 block down or (-4, -1) house 3 block east and 2 blocks north would be 3 blocks to the right and 2 blocks up or (3, 2) use the distance formula to find the distance between two points. That's all I know! hope this helps!~ just remember to use the distance formula to find the distance between two points.

5 0

3 years ago

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