I need help on math ASAP!!

Which of the following sets contain all roots of the polynomial

Zarrin [17]

All these given roots are contained in option C.

The given equation is :

$9x^{3}+9x^{2}-4x-4=0$

$9x^{2}(x+1)-4(x+1)=0$

$(9x^{2}-4)(x+1)=0$

$9x^{2}-4=0,x+1=0$

$x^{2}=\frac{4}{9},x=-1$

$x=\frac{2}{3},x=-1$

Roots = $-1,\frac{-2}{3} ,\frac{2}{3}$

Hence these lie in between $(\frac{-3}{2} ,\frac{3}{2})$

8 0

3 years ago

Crash Hospital Costs. A study was conducts to estimate hospital costs for accident victims who wore seat belts. Twenty randomly

kvv77 [185]

Answer:

a) The 99% confidence interval would be given by (5004.168;12603.832)

b) For this case we can use the lower bound for the confidence interval as estimation, on this case 5004.168. But we need to take in count that this value it's with 99% of confidence and 1% of significance and 1% of probability to commit type Error I

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".

$\bar X =9004$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s=5629 represent the sample standard deviation

n=20 represent the sample size

2) Part a

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

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

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=20-1=19$

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(0.005,19)".And we see that $t_{\alpha/2}=2.86$

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

$9004-2.86\frac{5629}{\sqrt{20}}=5004.168$

$9004+2.86\frac{5629}{\sqrt{20}}=12603.832$

So on this case the 99% confidence interval would be given by (5004.168;12603.832)

3) Part b

For this case we can use the lower bound for the confidence interval as estimation, on this case 5004.168. But we need to take in count that this value it's with 99% of confidence and 1% of significance and 1% of probability to commit type Error I

7 0

3 years ago

Given f (x) = 3x + 4, find f (2).

stealth61 [152]

$f(2) = 3 \cdot 2 + 4 = 6 + 4 = 10$

8 0

4 years ago

Which equation has x=2/3 as a solution and why?

eduard

There are an infinite number of different equations that have
x=2/3 as the solution, or as one of several solutions.

You didn't show us your list of choices, so we can't help you
pick the right one.

Just take each choice, one at a time. Write ' 2/3 ' in place of 'x'
in each equation, and simplify everything. You'll wind up with
one equation that's true, and the others will say something that's
nonsense.

The one that's true is the one that has x=2/3 as its solution.

6 0

3 years ago

Fill in the blanks to write this function when x=3

algol [13]

Answer:

Step-by-step explanation:

7 0

3 years ago

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