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3 years ago

I really need help thank you

Mathematics

1 answer:

lukranit [14]3 years ago

7 0

x^2 =144 has 2 solutions

x=sqrt(144)

x=+-12

x= 12 and x=-12

12*12 = 144 and (-12) * (-12) = 144

a square root has 1 positive and 1 negative solution

x^3 = 27

(x^3)^(1/3)=(27)^(1/3) ^(1/3) is the cube root

x = 3

it only has one solution because a negative * a negative * a negative would be negative

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Can someone check this one for me , thank you!

Rudik [331]

Answer:

Step-by-step explanation:

Using sum/difference to product identity

• sin x - sin y = 2 cos( $\frac{x+y}{2}$ ) sin ( $\frac{x-y}{2}$ )

with x = 4Θ and y = 2Θ

Then

sin(4Θ) - sin(2Θ)

= 2 cos( $\frac{4o+2o}{2}$ ) sin( $\frac{4o-2o}{2}$ )

= 2cos(3Θ)sinΘ → C

8 0

3 years ago

The Harper family is traveling to visit friends. The distance to the friend’s house is 276.45 miles. It takes the family 5.82 ho

Leona [35]

Answer:

270.63

Step-by-step explanation:

hope you get it right

8 0

3 years ago

Read 2 more answers

A group of biologists found a total of 15 loggerhead turtle nests along a beach during a certain season. This was 20% of the tot

Andre45 [30]

20% also equals 1/5, right?

So in order to find the total number of turtle nests, just find 5/5, or multiply 15 by 5.

15 x 5 = 75

There were 75 total nests

6 0

3 years ago

The realtor and her clients do not know the average home sale price for all of Guelph (500 was actually just a guess). However,

strojnjashka [21]

Answer:

a) The 99% confidence interval would be given by (346.708;453.292)

b) The 99% confidence interval would be given by (338.445;461.555)

Step-by-step explanation:

1) Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X=400$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

$\sigma=80$ represent the population standard deviation

n=15 represent the sample size

2) Part a

The confidence interval for the mean is given by the following formula:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

Since the Confidence is 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.005,0,1)".And we see that $z_{\alpha/2}=2.58$

Now we have everything in order to replace into formula (1):

$400-2.58\frac{80}{\sqrt{15}}=346.708$

$400+2.58\frac{80}{\sqrt{15}}=453.292$

So on this case the 99% confidence interval would be given by (346.708;453.292)

3) Part b

For this case we don't know the population deviation so we need to use the t distribution instead the normal standard distribution.

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

We need to find the degrees of freedom first df=n-1=15-1=14

Since the Confidence is 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.005,14)".And we see that $t_{\alpha/2}=2.98$

Now we have everything in order to replace into formula (1):

$400-2.98\frac{80}{\sqrt{15}}=338.445$

$400+2.98\frac{80}{\sqrt{15}}=461.555$

So on this case the 99% confidence interval would be given by (338.445;461.555)

4 0

3 years ago

Which is equivalent to 216 1/3? A.3 B.6 C.36 D.72

nydimaria [60]

The 1/3 power is another way to write the cube root.
∛216 = 6

3 0

3 years ago