Answer the questions in the image attached.

An engineer has designed a valve that will regulate water pressure on an automobile engine. The valve was tested on 180180 engin

tiny-mole [99]

Answer:

$z=\frac{4.6-4.8}{\frac{0.9}{\sqrt{180}}}=-2.98$

$p_v =P(Z$

If we compare the p value and the significance level given $\alpha=0.1$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis,and we have enough evidence to conclude that the true mean is significantly lower thn 4.8 at 10% of signficance.

Step-by-step explanation:

Data given and notation

$\bar X=4.6$ represent the sample mean

$\sigma=0.9$ represent the population standard deviation

$n=180$ sample size

$\mu_o =4.8$ represent the value that we want to test

$\alpha=0.1$ represent the significance level for the hypothesis test.

z would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if thetrue mean is below the specifications, the system of hypothesis would be:

Null hypothesis: $\mu \geq 4.8$

Alternative hypothesis: $\mu < 4.8$

If we analyze the size for the sample is > 30 and we know the population deviation so is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$z=\frac{4.6-4.8}{\frac{0.9}{\sqrt{180}}}=-2.98$

P-value

Since is a one sided test the p value would be:

$p_v =P(Z$

Conclusion

If we compare the p value and the significance level given $\alpha=0.1$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis,and we have enough evidence to conclude that the true mean is significantly lower thn 4.8 at 10% of signficance.

4 0

3 years ago

Triangles abc, dbe, and fbg are all symmetric about the y-axis. what are the coordinates of the centroid?

Drupady [299]

Answer:

The coordinates of the centroid are (0, 5)

Step-by-step explanation:

The coordinates of the centroid of a triangle whose vertices (x1, y1), (x2, y2), and (x3, y3) are ( $\frac{x1+x2+x3}{3}$ , $\frac{y1+y2+y3}{3}$ )

In Δ ABC

∵ A = (-20, 0), B = (0, 15), C = (20, 0)

∴ x1 = -20, x2 = 0, x3 = 20

∴ y1 = 0, y2 = 15, y3 = 0

∴ The centroid = ( $\frac{-20+0+20}{3}$ , $\frac{0+15+0}{3}$ ) = ( $\frac{0}{3}$ , $\frac{15}{3}$ ) = (0, 5)

∴ The coordinates of the centroid of Δ ABC are (0, 5)

In Δ DBE

∵ D = (-15, 0), B = (0, 15), E = (15, 0)

∴ x1 = -15, x2 = 0, x3 = 15

∴ y1 = 0, y2 = 15, y3 = 0

∴ The centroid = ( $\frac{-15+0+15}{3}$ , $\frac{0+15+0}{3}$ ) = ( $\frac{0}{3}$ , $\frac{15}{3}$ ) = (0, 5)

∴ The coordinates of the centroid of Δ DBE are (0, 5)

In Δ FBG

∵ F = (-5, 0), B = (0, 15), G = (5, 0)

∴ x1 = -5, x2 = 0, x3 = 5

∴ y1 = 0, y2 = 15, y3 = 0

∴ The centroid = ( $\frac{-5+0+5}{3}$ , $\frac{0+15+0}{3}$ ) = ( $\frac{0}{3}$ , $\frac{15}{3}$ ) = (0, 5)

∴ The coordinates of the centroid of Δ FBG are (0, 5)

∵ The three triangles are symmetric about the y-axis

→ That means they have the same centroid and it lies on the y-axis

∴ The coordinates of the centroid are (0, 5)

8 0

3 years ago

What is 16 tens + 4 ones

aalyn [17]

(16*0) + (4*1)
16*10 = 160
4*1 = 4
160 + 4
The answer is 164! :)

5 0

3 years ago

Read 2 more answers

The subject of the formula below is y.<br>a=4x/t - p<br>Rearrange the f make x the subject.

Crazy boy [7]

Answer:

x = t(a+p)/4

Step-by-step explanation

Given the expression

a=4x/t - p

We are to make x the subject of the formula

a=4x/t - p

Add p to both sides

a+p = 4x/t - p+p

a+p = 4x/t

Cross multiply

t(a+p) = 4x

Rearrange

4x = t(a+p)

Divide both sides by 4

4x/4 = t(a+p)/4

x = t(a+p)/4

4 0

3 years ago

Need help can anyone help me???

Paladinen [302]

Answer:

it is greater than 45°

Step-by-step explanation:

From the relationship of angles and secants/tangents, we have ...

m∠GSO = (long arc GO -arc GT)/2

Solving for (long arc GO), we have ...

2(m∠GSO) +arc GT = (long arc GO)

We know that (long arc GO) > 180°, so we can write ...

2(m∠GSO) +90° > 180° . . . . arc GT = 90°

2(m∠GSO) > 90° . . . . . . subtract 90°

m∠GSO > 45° . . . . . . . . divide by 2

_____

<em>Alternate solution</em>

Inscribed ∠GOT has half the measure of arc GT, so is 45°.

You know that if angle G were 90°, then the right triangle would be isosceles, and angle S would also be 45°. In this triangle, arc GTO is less than 180°, so angle G is less than 90°.

When angle G gets smaller, the sum of angles remains the same, so angle S must be larger than 45°.

This reasoning is written more formally in the math above.

8 0

3 years ago