30x + 20y +55 ANSWER ASAP

Higher-order thinking What two multiplication tables can help you find 3x 9? How could you use 3 x 9 to find 9 x 3?

babunello [35]

Answer:

Its simple if you will multiple 3 by 9 the answer will be 27 and if we multiple 9 by 3 so the answer will be same 27.

Step-by-step explanation:

Thank you..

8 0

3 years ago

Write 825 million in scientific notation.<br> please show your work

True [87]

Answer:

8.5* $10^7$

Step-by-step explanation:

825 million is

825,000,000

so you need to do 8.25 and then 10 to the power of 8

so the answer is 8.5* $10^8$

5 0

3 years ago

An accounting firm is planning for the next tax preparation season. From last years returns, the firm collects a systematic rand

Elena L [17]

Answer:

a)From the central limit theorem we know that the distribution for the sample mean $\bar X$ is given by:

$\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})$

And the standard error for the mean would be:

$\sigma_{\bar X}= \frac{140}{\sqrt{100}} =14$

b) We want this probability:

$P(\bar X >120)$

And we can use the z score formula given by:

$z = \frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n}}}$

And replacing we got:

$z = \frac{120-90}{\frac{140}{\sqrt{100}}}= 2.143$

And we can find this probability with the complement rule and the normal standard deviation or excel and we got:

$P( z>2.143) = 1-P(Z$

Step-by-step explanation:

Previous concepts

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".

The central limit theorem states that "if we have a population with mean μ and standard deviation σ and take sufficiently large random samples from the population with replacement, then the distribution of the sample means will be approximately normally distributed. This will hold true regardless of whether the source population is normal or skewed, provided the sample size is sufficiently large".

Solution to the problem

Part a

From the central limit theorem we know that the distribution for the sample mean $\bar X$ is given by:

$\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})$

And the standard error for the mean would be:

$\sigma_{\bar X}= \frac{140}{\sqrt{100}} =14$

Part b

We want this probability:

$P(\bar X >120)$

And we can use the z score formula given by:

$z = \frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n}}}$

And replacing we got:

$z = \frac{120-90}{\frac{140}{\sqrt{100}}}= 2.143$

And we can find this probability with the complement rule and the normal standard deviation or excel and we got:

$P( z>2.143) = 1-P(Z$

4 0

3 years ago

Find the volume of the sphere with 3ft

Ilia_Sergeevich [38]

Answer:

Step-by-step explanation:

V=4/3πr^3

V=1.333×3.14×27ft

V=113.04ft

5 0

3 years ago

A boat is 2000m from a cliff. If the angle of depression from the top of the cliff to the boat is 10 degrees, how tall is the cl

lubasha [3.4K]

Answer:

Let AB is the height of the cliff = H and p is the posit ion of the boat.Angle of depression= angle of elevation= 15 degrees therefore angle APB= 15 degrees tan 15=AB=h/1,000 h=(1,000)*tan 15=(1,000)(0.26794919243112)=268.94919243112 meters or

Simply: 268meters..........Ans

6 0

3 years ago

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