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3 years ago

MaFind the co-ordinate the image of a point 6,4). Rotate it than270de acee

Mathematics

1 answer:

telo118 [61]3 years ago

6 0

Answer:

(4, - 6 )

Step-by-step explanation:

Under a counterclockwise rotation about the origin of 270°

a point (x, y ) → (y, - x ) , thus

(6, 4 ) → (4, - 6 )

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Help me with this question please!! Show all work

Valentin [98]

The answer is 439.

3+(1/(7+1/15) = 333/106

333+ 106 = 439.

8 0

2 years ago

-2(1.7x + 3.1) = 4 find x please

katrin2010 [14]

Answer:

x=-3

Step-by-step explanation:

you first distribute -2 then add 6.2 to both sides of the equation the finnaly divide by -3.4 to both side then you will get x

(-2)1.7x+(-2)3.1`

-3.4x-6.2=4

+6.2 +6.2

-3.4x=10.2

-3.4x/-3.4= 10.2/-3.4

x=-3

6 0

2 years ago

A manufacturer produces crankshafts for an automobile engine. the crankshafts wear after 100,000 miles (0.0001 inch) is of inter

Daniel [21]

Part A:

Significant level:

α = 0.05

Null and alternative hypothesis:

h0 : μ = 3 vs h1: μ ≠ 3

Test statistics:

$z= \frac{\bar{x}-\mu}{\sigma/\sqrt{n}} \\ \\ = \frac{2.78-3}{0.9/\sqrt{15}} \\ \\ = \frac{-0.22}{0.2324} =-0.9467$

P-value:

P(-0.9467) = 0.1719

Since the test is a two-tailed test, p-value = 2(0.1719) = 0.3438

Conclusion:

Since the p-value is greater than the significant level, we fail to reject the null hypothesis and conclude that there is no sufficient evidence that the true mean is different from 3.

Part B:

The power of the test is given by:

$\beta=\phi\left(Z_{0.025}+ \frac{3-3.25}{0.9/\sqrt{15}}\right) -\phi\left(-Z_{0.025}+ \frac{3-3.25}{0.9/\sqrt{15}}\right) \\ \\ =\phi\left(1.96+ \frac{-0.25}{0.2324} \right)-\phi\left(-1.96+ \frac{-0.25}{0.2324} \right)=\phi(0.8842)-\phi(-3.0358) \\ \\ =0.8117-0.0012=0.8105$

Therefore, the power of the test if μ = 3.25 is 0.8105.

Part C:

The sample size that would be required to detect a true mean of 3.75 if we wanted the power to be at least 0.9 is obtained as follows:

$1-0.9=\phi\left(Z_{0.025}+ \frac{3-3.75}{0.9/\sqrt{n}}\right) -\phi\left(-Z_{0.025}+ \frac{3-3.75}{0.9/\sqrt{n}}\right) \\ \\ \Rightarrow0.1=\phi\left(1.96+ \frac{-0.75}{0.9/\sqrt{n}}\right)-\phi\left(-1.96+ \frac{-0.75}{0.9/\sqrt{n}} \right) \\ \\ =\phi\left(1.96+(-3.2415)\right)-\phi\left(1.96+(-3.2415)\right) \\ \\ \Rightarrow\frac{-0.75}{0.9/\sqrt{n}}=-3.2415 \\ \\ \Rightarrow\frac{0.9}{\sqrt{n}}=\frac{-0.75}{-3.2415}=0.2314 \\ \\ \Rightarrow\sqrt{n}=\frac{0.9}{0.2314}=3.8898$

$\Rightarrow n=(3.8898)^2=15.13$

Therefore, the sample size that would be required to detect a true mean of 3.75 if we wanted the power to be at least 0.9 is 16.

8 0

2 years ago

A round pipe 4 ft long and 8 in in diameter connects an outdoor water tank to a hot tub.

dlinn [17]

The volume of a cylinder is pir^2h. So the answer is pi*4^2 times 4. 64 pi.

8 0

2 years ago

Find the zeros of the function and write in a+bi form. -(x+1)^2-4=0

GrogVix [38]

Answer:

x = -(1 + 4i)

or x = -1+4i

Step-by-step explanation:

From what we have;

-(x + 1)^2 = 4

(x + 1)^2 = -4

x + 1 = √-4

x + 1 = -4i or 4i

x = -1 - 4i or -1 + 4i

3 0

2 years ago

MaFind the co-ordinate the image of a point 6,4). Rotate it than270de acee​

MaFind the co-ordinate the image of a point 6,4). Rotate it than270de acee