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The equation for the circle below is x^2+y^2=64 what is the length of the circle’s radius

FromTheMoon [43]

Answer:

Step-by-step explanation:

The standard form of an equation of a circle:

$(x-h)^2+(y-k)^2=r^2$

(h, k) - center

r - radius

We have the equation:

$x^2+y^2=64\\\\(x-0)^2+(y-0)^2=8^2$

Therefore the center is (0, 0) and the radius r = 8

3 0

3 years ago

Use the power property to rewrite log3x9.

posledela

For properties of logarithm we have the following:
loga (x ^ b) = b * loga (x)
Therefore, following this property we have for this case:
log3 (x ^ 9) = 9log3 (x)
Answer:
the power property to rewrite log3x9 is:
B) 9log3x

4 0

3 years ago

Read 2 more answers

It is claimed that automobiles are driven on average more than 20,000 kilometers per year. To test this claim, 100 randomly sele

kow [346]

Answer:

$t=\frac{23500-20000}{\frac{3900}{\sqrt{100}}}=8.974$

$p_v =P(t_{99}>8.974)=9.43x10^{-15}$

If we compare the p value and the significance level given for example $\alpha=0.05$ we see that $p_v$ so we can conclude that we to reject the null hypothesis, and the actual mean is significantly higher than 20000.

Step-by-step explanation:

1) Data given and notation

$\bar X=23500$ represent the sample mean

$s=3900$ represent the sample standard deviation

$n=100$ sample size

$\mu_o =2000$ represent the value that we want to test

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

t 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 determine if the true mean is higher than 20000, the system of hypothesis would be:

Null hypothesis: $\mu \leq 2000$

Alternative hypothesis: $\mu > 2000$

We don't know the population deviation, so for this case is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

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

t-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:

$t=\frac{23500-20000}{\frac{3900}{\sqrt{100}}}=8.974$

Calculate the P-value

First we need to calculate the degrees of freedom given by:

$df=n-1=100-1=99$

Since is a one-side upper test the p value would be:

$p_v =P(t_{99}>8.974)=9.43x10^{-15}$

Conclusion

If we compare the p value and the significance level given for example $\alpha=0.05$ we see that $p_v$ so we can conclude that we to reject the null hypothesis, and the actual mean is significantly higher than 20000.

8 0

3 years ago

For which value of x must the expression square root of 19x be further simplified? A. 15. B 21. C 28. D 41

algol [13]

<span>The expression of the square root of 19x must be simplified when x is equal to 28. This is because possible factors of 28 can be seen to be 4 and 7, and 4 is a perfect square. This means it can be pulled outside of the square root when evaluated. The other options include only prime factors that could not be pulled out. (3,5), (3,7), (1,41)
28 simplifies as such:
Sqrt(19*28) = Sqrt(19*4*7) = 2*Sqrt(19*7) = 2*Sqrt(133).</span>

5 0

3 years ago

Read 2 more answers

1.5 times 10 by the power of 4

Murrr4er [49]

You can write
1.5
⋅
10
5
=
15
⋅
10
4
15
⋅
10
4
−
8
⋅
10
4
=
(
15
−
8
)
⋅
10
4
=
7
⋅
10
4
Since the power is positive we move the dec.point 4 to the right:
=
70000

Hope it works

4 0

3 years ago

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