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3 years ago

14

the distance d a train travela varies directly with the amount of time t that has elapse since departure. If the train travela 4

75 miles in 9.5 hours, how many miles did the train travel after 4hours

1 answer:

antiseptic1488 [7]3 years ago

7 0

475/9.5 x4 = 200miles in 4hrs

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Find x pretty please

mario62 [17]

Answer:

100⁰

because this is a quadrilateral inscribed in the circle

=> x + 80 = 180

<=> x = 180 - 80 = 100⁰

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3 years ago

A rocket is launched from a tower. The height of the rocket, y in feet, is related to the time after launch, x in seconds, by th

olchik [2.2K]

Answer:

14.52 seconds.

Step-by-step explanation:

We have been given that the height of the rocket, y in feet, is related to the time after launch, x in seconds, by the given equation $y=-16x^2+224x+121$ . We are asked to find the time, when the rocket will hit the ground.

We know that the rocket will hit the ground, when height will be 0. So to find the time when rocket will hit the ground, we will substitute $y=0$ in our given equation as:

$0=-16x^2+224x+121$

Let us solve for x using quadratic formula.

$x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$

$x=\frac{-224\pm\sqrt{224^2-4(-16)(121)}}{2(-16)}$

$x=\frac{-224\pm\sqrt{50176+7744}}{-32}$

$x=\frac{-224\pm\sqrt{57920}}{-32}$

$x=\frac{-224\pm240.66574}{-32}$

$x=\frac{-224+240.66574}{-32}, x=\frac{-224-240.66574}{-32}$

$x=\frac{16.66574}{-32}, x=\frac{-464.66574}{-32}$

$x=-0.520804375, x=14.520804375$

Upon rounding to nearest 100th of second, we will get:

$x\approx -0.52, x\approx 14.52$

Since time cannot be negative, therefore, the rocket will hit the ground after 14.52 seconds.

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4 years ago

Read 2 more answers

The number of boots that 25 students had in their homes in Florida were recorded

wolverine [178]

Answer:

Min = 0; Q₁ = 0; Median = 2; Q₃ = 2; Max = 8

Step-by-step explanation:

Assume that your sorted data are

0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 4, 5, 8

1. Minimum

Min = 0

2. Median

The median is the middle value in a sorted data set. There are 25 items, so the median is the 13th item.

Median = 2

3. First quartile

Q₁ is the median of the lower half of the data set.

The median of 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2 is 0.

Q₁ = 0

4. Third quartile

Q₃ is the median of the upper half of the data set.

The median of 2, 2, 2, 2, 2, 3, 3, 3, 3, 4, 5, 8 is 3.

Q₃ = 3

5. Maximum

Max = 8

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3 years ago

Graph or explain how to graph on a coordinate plane: x = 5

zhenek [66]

Answer: look for your positive side and look on the line that goes from side to side and find 5 and draw a line up and down thru the 5

Step-by-step explanation:

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4-13 Students in a management science class have just re- ceived their grades on the first test. The instructor has provided inf

inessss [21]

Answer:

a) y = 0.74x + 18.99; b) 80; c) r = 0.92, r² = 0.85; r² tells us that 85% of the variance in the dependent variable, the final average, is predictable from the independent variable, the first test score.

Step-by-step explanation:

For part a,

We first plot the data using a graphing calculator. We then run a linear regression on the data.

In the form y = ax + b, we get an a value that rounds to 0.74 and a b value that rounds to 18.99. This gives us the equation

y = 0.74x + 18.99.

For part b,

To find the final average of a student who made an 83 on the first test, we substitute 83 in place of x in our regression equation:

y = 0.74(83) + 18.99

y = 61.42 + 18.99 = 80.41

Rounded to the nearest percent, this is 80.

For part c,

The value of r is 0.92. This tells us that the line is a 92% fit for the data.

The value of r² is 0.85. This is the coefficient of determination; it tells us how much of the dependent variable can be predicted from the independent variable.

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3 years ago