Factor completely 2x^2-40x+200

Iteru [2.4K]

Get rid of brackets:
21x +6 +8x
Put 6 to the other side:
21x +8x = -6
27x = -6
Divide both sides by 27
X= -0.22

3 0

3 years ago

The valve was tested on 270 engines and the mean pressure was 6.6 lbs/square inch. Assume the variance is known to be 0.49. If t

BlackZzzverrR [31]

Answer:

$z=\frac{6.6-6.5}{\frac{0.7}{\sqrt{270}}}=2.347$

The p value for this case would be given by"

$p_v =2*P(z>2.347)=0.0189$

For this case since the p value is higher than the significance level we don't have enough evidence to conclude that the true mean is significantly different from 6.5 lbs/square inch at 10% of significance. So then there is not enough evidence to conclude that the valve does not perform to the specifications

Step-by-step explanation:

Information given

$\bar X=6.6$ represent the sample mean

$s=\sqrt{0.49}= 0.7$ represent the population deviation

$n=270$ sample size

$\mu_o =6.5$ represent the value that we want to test

$\alpha=0.1$ represent the significance level

z would represent the statistic

$p_v$ represent the p value for the test

Hypothesis to verify

We want to verify if the true mean for this case is equal to 6.5 lbs/square inch or not , the system of hypothesis would be:

Null hypothesis: $\mu= 6.5$

Alternative hypothesis: $\mu \neq 6.5$

The statistic for this case is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

And replacing we got:

$z=\frac{6.6-6.5}{\frac{0.7}{\sqrt{270}}}=2.347$

The p value for this case would be given by"

$p_v =2*P(z>2.347)=0.0189$

For this case since the p value is higher than the significance level we don't have enough evidence to conclude that the true mean is significantly different from 6.5 lbs/square inch at 10% of significance. So then there is not enough evidence to conclude that the valve does not perform to the specifications

8 0

4 years ago

What is the image of (1, -6) for a 180° counterclockwise rotation about the origin?

a_sh-v [17]

Answer: option b

Step-by-step explanation:

It is important to know that, by definition, the rule for 180 degrees counterclockwise rotation is:

$(x,y)$ → $(-x,-y)$

Therefore, given the point (1, -6) we can find the image obtained for for a 180° counterclockwise rotation about the origin by applying the rule mentioned before.

Then, the image is:

$(1,-6)$ → $(-(1),-(-6))=(-1,6)$