What cannot be separated into simpler substances by physical or mechanical methods

PLEASE HELP

pogonyaev

Answer:

b and c

Step-by-step explanation:

both slopes are 2/3

6 0

3 years ago

Data is collected to compare two different types of batteries. We measure the time to failure of 12 batteries of each type. Batt

-Dominant- [34]

Using the t-distribution, it is found that since the test statistic is greater than the critical value for the right-tailed test, it is found that there is enough evidence to conclude that Battery B outlasts Battery A by more than 2 hours.

At the null hypothesis, it is tested if it does not outlast by more than 2 hours, that is, the subtraction is not more than 2:

$H_0: \mu_B - mu_A \leq 2$

At the alternative hypothesis, it is tested if it outlasts by more than 2 hours, that is:

$H_1: \mu_B - \mu_A > 2$

The sample means are: $\mu_A = 8.65, \mu_B = 11.23$

The standard deviations for the samples are $s_A = s_B = 0.67$

Hence, the standard errors are:

$s_{Ea} = S_{Eb} = \frac{0.67}{\sqrt{12}} = 0.1934$

The distribution of the difference has mean and standard deviation given by:

$\overline{x} = \mu_B - \mu_A = 11.23 - 8.65 = 2.58$

$s = \sqrt{s_{Ea}^2 + s_{Eb}^2} = \sqrt{0.1934^2 + 0.1934^2} = 0.2735$

The test statistic is given by:

$t = \frac{\overline{x} - \mu}{s}$

In which $\mu = 2$ is the value tested at the hypothesis.

Hence:

$t = \frac{\overline{x} - \mu}{s}$

$t = \frac{2.58 - 2}{0.2735}$

$t = 2.12$

The critical value for a right-tailed test, as we are testing if the subtraction is greater than a value, with a 0.05 significance level and 12 + 12 - 2 = 22 df is given by $t^{\ast} = 1.71$

Since the test statistic is greater than the critical value for the right-tailed test, it is found that there is enough evidence to conclude that Battery B outlasts Battery A by more than 2 hours.

A similar problem is given at brainly.com/question/13873630

7 0

3 years ago

Half a number plus 2.5 times that number equals 18. What is the number?

mixas84 [53]

Tua madre Puttana quella troia inculata schifosa

6 0

3 years ago

the width of the morros in shannon's bathroom is 4/9 its length. The area of the mirror is 576 square inches. What are the dimen

fredd [130]

W=4L/9

A=LW, using W found above gives us

A=L(4L/9)

A=4L^2/9 and we were told that A=576 so

4L^2/9=576 multiply both sides by 9

4L^2=5184 divide both sides by 4

L^2=1296 take the square root of both sides

L=36, and we know that W=4L/9 so

W=4(36/9)=16

So the dimensions are: width=16in and length=36in

5 0

4 years ago

Systems of equations and inequalities solving systems by elimination {y= -x+1 {y= 4x-14

kodGreya [7K]

Answer:

x = 3 , y = -2

Step-by-step explanation:

Solve the following system:

{y = 1 - x | (equation 1)

y = 4 x - 14 | (equation 2)

Express the system in standard form:

{x + y = 1 | (equation 1)

-(4 x) + y = -14 | (equation 2)

Swap equation 1 with equation 2:

{-(4 x) + y = -14 | (equation 1)

x + y = 1 | (equation 2)

Add 1/4 × (equation 1) to equation 2:

{-(4 x) + y = -14 | (equation 1)

0 x+(5 y)/4 = (-5)/2 | (equation 2)

Multiply equation 2 by 4/5:

{-(4 x) + y = -14 | (equation 1)

0 x+y = -2 | (equation 2)

Subtract equation 2 from equation 1:

{-(4 x)+0 y = -12 | (equation 1)

0 x+y = -2 | (equation 2)

Divide equation 1 by -4:

{x+0 y = 3 | (equation 1)

0 x+y = -2 | (equation 2)

Collect results:

Answer: {x = 3 , y = -2

5 0

4 years ago

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