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3 years ago

What is 2x-5y+15=0 written in slope-intercept form

2 answers:

8 0

<span>slope intercept form is " y = mx + b ". 2x - 5y + 15 = 0 we have to get -5y on one side, so we will add 5y to both sides 2x + 15 = 5y now we have to divide by 5 to get y by itself (2x + 15)/5 = y 2/5x + 3 = y which equals y = 2/5x + 3</span>

Nadya [2.5K]3 years ago

6 0

The answer is y=2/5x+3

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Math proportions..............

gogolik [260]

9/x = 25/100

cross multiple to get:

25x = 900

then divide to simply:

x=36

4 0

3 years ago

Joanne has a cylindrical, above ground pool. the depth (height) of the pool is 1/2 of its radius, and the volume is 1570 cubic f

scoundrel [369]

Answer:

$\sqrt[3]{3140^2\pi}\approx 146.41\ ft^2$

Step-by-step explanation:

The volume of the cylinder is

$V_{cylinder}=\pi r^2\cdot H,$

where r is the base radius and H is the height.

Since $H=\dfrac{1}{2}r$ and V=1570 cubic feet, then

$1570=\pi r^2\cdot \dfrac{r}{2},\\ \\1570=\dfrac{\pi r^3}{2},\\ \\r^3=\dfrac{3140}{\pi},\\ \\r=\sqrt[3]{\dfrac{3140}{\pi}}\ ft.$

The area of its bottom floor is

$A_{floor}=\pi r^2=\pi\cdot \left(\sqrt[3]{\dfrac{3140}{\pi}}\right)^2= \sqrt[3]{3140^2\pi}\approx 146.41\ ft^2.$

6 0

3 years ago

I really need help on these two questions

Yuri [45]

$(4^\frac{1}{3} )^3$ =4
$(6^ \frac{1}{6} )^6$ =6
$(3^ \frac{1}{2} )^4$ =
multiply $\frac{1}{2}$ by 4
and then simplify
$3^{2}$

so it will be
4x6x9=216
your answer is d.216

3 0

3 years ago

An investigator compares the durability of two different compounds used in the manufacture of a certain automobile brake lining.

strojnjashka [21]

Answer:

1. The 90% confidence interval for the true difference between average lifetimes for brakes using Compound 1 and brakes using Compound 2 is (-2411.84, -1332.16).

2. The point estimate for the true difference between the population means is of -1872.

Step-by-step explanation:

Before building the confidence interval, we need to understand the central limit theorem and subtraction between normal variables.

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 $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Subtraction of Normal Variables:

When two normal variables are subtracted, the mean is the subtraction of the means while the standard deviation is the square root of the sum of the variances.

A sample of 212 brakes using Compound 1 yields an average brake life of 47,895 miles. The population standard deviation for Compound 1 is 1590 miles.

This means that $\mu_1 = 47895, \sigma_1 = 1590, n = 212, s_1 = \frac{1590}{\sqrt{212}} = 109.2$

A sample of 180 brakes using Compound 2 yields an average brake life of 49,767 miles. The population standard deviation for Compound 2 is 4152 miles.

This means that $\mu_2 = 49767, \sigma_2 = 4152, n = 180, s_2 = \frac{4152}{\sqrt{180}} = 309.47$

True difference between average lifetimes for brakes using Compound 1 and brakes using Compound 2.

This is the distribution 1 - 2. So

$\mu = \mu_1 - \mu_2 = 47895 - 49767 = -1872$

This is also the point estimate for the true difference between the population means, which is question 2.

$s = \sqrt{s_1^2+s_2^2} = \sqrt{109.2^2+309.47^2} = 328.17$

90% confidence interval

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1 - 0.9}{2} = 0.05$

Now, we have to find z in the Ztable as such z has a pvalue of $1 - \alpha$ .

That is z with a pvalue of $1 - 0.05 = 0.95$ , so Z = 1.645.

Now, find the margin of error M as such

$M = zs = 1.645*328.17 = 539.84$

The lower end of the interval is the sample mean subtracted by M. So it is -1872 - 539.84 = -2411.84

The upper end of the interval is the sample mean added to M. So it is -1872 + 539.84 = -1332.16.

The 90% confidence interval for the true difference between average lifetimes for brakes using Compound 1 and brakes using Compound 2 is (-2411.84, -1332.16).

5 0

4 years ago

-2(x-3)-2<br> simplify the expression

Rashid [163]

Answer:

-2x+4

Step-by-step explanation:

-2(x-3)-2

-2x+6-2

-2x+4

4 0

3 years ago