HELP PLEASE!!<br><br>8 points!

What which relationship in each of the following represents a Non-proportional relationship

sergij07 [2.7K]

The answer is C y =3.5x

6 0

3 years ago

Which equation can be used to solve for in the following diagram?

Ivahew [28]

Answer:

the Answer is 3x+12)+X=180

5 0

3 years ago

A bridge is sketched in the coordinate plane as a parabola represented by the equation h=40-0.01x2, where h refers to the height

ElenaW [278]

Answer:

The length of the bridge is 126.492 feet.

Step-by-step explanation:

Let $h(x) = 40-0.01\cdot x^{2}$ , where $x$ is the position from the middle of the bridge, measured in feet, and $h(x)$ is the height of the bridge at a location of x feet, measured in feet. In this case, the length of the bridge is represented by the distance between the x-intercepts of the parabola, which we now find by factorization:

$40-0.01\cdot x^{2} = 0$ (Eq. 1)

$x^{2} = \frac{40}{0.01}$

$x =\pm \sqrt{\frac{40}{0.01} }$

$x = \pm 63.246\,ft$

Given that the parabola is symmetrical with respect to y-axis, then the length is two times the magnitude of the value found above, that is:

$l = 2\cdot (63.246\,ft)$

$l = 126.492\,ft$

The length of the bridge is 126.492 feet.

3 0

3 years ago

What is the maximum volume in cubic inches of an open box to be made from a 10- inch by 20-inch piece of cardboard by cutting ou

Mekhanik [1.2K]

Answer:

192.5 in³

Step-by-step explanation:

The cardboard is 10 by 20 before removing a square from each end. Assuming that the square is x inches wide. Therefore, the 20 in side gets reduced by x inches on both sides, or say it becomes 20 - 2x inches. On the other hand, the 10 in side is also reduced by 2x. The x value we get happens to be the height of the box when the sides are folded up.

Thus the volume V = lbh =

V = (20-2x)*(10-2x)*(x)

V = 4x³ - 60x² + 200x

On differentiating, we have dv/dx to be

dv/dx = 12x² - 120x + 200

Using general formula to find the roots of this equation, we can solve that x = 7.886 and x = 2.113

This roots we got are possible values of x, the square we cut. Since 7.886 * 2 = 15.772 inches, this is more than the 10 inch side, henceforth x = 2.113 inches.

You cut 2.113 inches from each corner to obtain the maximum volume.

The sizes of the cubes are

20 - (2 * 2.113) = 15.774

10 - (2 * 2.113) = 5.774

2.113

The volume of the cube is 15.774 * 5.774 * 2.113 = 192.5 cubic inches.

8 0

3 years ago

A researcher reports survey results by stating that the standard error of the mean is 25 the population standard deviation is 40

bezimeni [28]

Answer:

a) A sample of 256 was used in this survey.

b) 45.14% probability that the point estimate was within ±15 of the population mean

Step-by-step explanation:

This question is solved using the normal probability distribution and the central limit theorem.

Normal probability distribution

When the distribution is normal, we use 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.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .