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3 years ago

20 points plz help me out

Mathematics

1 answer:

poizon [28]3 years ago

3 0

Answer:

13) x=5

14) x=70

16) x=42

Step-by-step explanation:

Couldn't read 15 sorry

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HELP WITH ANGLES AGain LOL

Semmy [17]

Answer: 180
Explanation: just ask me for it

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2 years ago

4x^2+2x-1=0 in quaratic equations

Viktor [21]

Answer:

Step-by-step explanation:

"quaratic" should be "quadratic."

The coefficients of this quadratic are 4, 2 and -1. Thus, the discriminant is

b^2 - 4ac, or here, 4 - 4(4)(-1) = 20

Since the discriminant is positive, our quadratic has two real, different roots.

-2 ± (√4)(√5)

The roots are: x = ---------------------

2(4)

-1 ± √5

This reduces to x = ---------------

5 0

3 years ago

Is a vertical line perpendicular to the x-axis

borishaifa [10]

A vertical line is perpendicular to the x-axis because they would intersect to form a 90 degree angle.

5 0

3 years ago

Read 2 more answers

D-75 DIVIDE by 8 =2 <br> sovle step by step eqation

Kobotan [32]

Answer:

7.3

Step-by-step explanation:

D-75÷8=2

P.E.M.D.A.S

parenthesis, exponents, multiplication, division, addition, subtraction

Which on comes first would be

Division

75÷8= 9.3-D=2

9.3

-2.0

-----

7.3

So, D would equal 7.3.

7 0

3 years ago

The US Census reported that it takes workers an average of 28 minutes to get home from work with standard deviation 5 minutes. A

xz_007 [3.2K]

Using the z-distribution, as we have the standard deviation for the population, to test the hypothesis, it is found that this is evidence that workers in the large city take longer than 28 minutes to get home from work.

<h3>What are the hypothesis tested?</h3>

At the null hypothesis, it is tested if the mean time is of 28 minutes, that is:

$H_0: \mu = 28$

At the alternative hypothesis, it is tested if the mean time is greater than 28 minutes, that is:

$H_1: \mu > 28$ .

<h3>What is the test statistic?</h3>

The test statistic is given by:

$z = \frac{\overline{x} - \mu}{\frac{\sigma}{\sqrt{n}}}$

The parameters are:

$\overline{x}$ is the sample mean.

$\mu$ is the value tested at the null hypothesis.

$\sigma$ is the standard deviation of the sample.

n is the sample size.

In this problem, the values of the parameters are given by:

$\overline{x} = 32, \mu = 28, \sigma = 5, n = 10$

Hence:

$z = \frac{\overline{x} - \mu}{\frac{\sigma}{\sqrt{n}}}$

$z = \frac{32 - 28}{\frac{5}{\sqrt{10}}}$

$z = 2.53$

<h3>What is the decision?</h3>

Considering that we have a <em>right-tailed test</em>, as we are testing if the mean is greater than a value, with a standard <em>significance level of 0.05</em>, the critical value is of $z^\ast = 1.645$ .

Since the test statistic is greater than the critical value, it is found that this is evidence that workers in the large city take longer than 28 minutes to get home from work.

To learn more about the z-distribution, you can check brainly.com/question/26454209

4 0

2 years ago