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3 years ago

Find the solution set x^2+2x-8=0 separate the two answers with a comma

Mathematics

1 answer:

EastWind [94]3 years ago

3 0

Answer:

-4, 2

Step-by-step explanation:

The equation can be factored as ...

(x +4)(x -2) = 0

This has solutions that make the factors zero:

x = -4, x = 2

The solution set is {-4, 2}.

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Suppose that the epidemiologist wants to re-estimate the population proportion and wishes for her 95% confidence interval to hav

Svetllana [295]

Answer:

She needs a sample of at least 385.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

The margin of error is:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

95% confidence level

So $\alpha = 0.05$ , z is the value of Z that has a pvalue of $1 - \frac{0.05}{2} = 0.975$ , so $Z = 1.96$ .

How large a sample should she take to achieve this?

She needs a sample of size at least n.

n is found when M = 0.04.

We do not know the true population proportion, so we use $\pi = 0.5$ , which is the case for which we are going to need the largest sample size.

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.05 = 1.96\sqrt{\frac{0.5*0.5}{n}}$

$0.05\sqrt{n} = 1.96*0.5$

Dividing both sides by 0.05

$\sqrt{n} = 19.6$

$(\sqrt{n})^{2} = 19.6^{2}$

$n = 384.2$

Rounding up

She needs a sample of at least 385.

3 0

3 years ago

What do scientists usually do if they can't draw clear conclusions?

Dmitry_Shevchenko [17]

Answer:

B. collect more data to support their hypothesis.

D. something the data do not directly show, but that can be found indirectly.

A. agree with the hypothesis.

Step-by-step explanation:

8 0

3 years ago

If there are 4 boys and 6 girls write each of the following as a ratio: boys to girls and girls to people.

sesenic [268]

Step-by-step explanation:

i hope it is the right answer

6 0

3 years ago

Read 2 more answers

H(n)=n³+4. Find h(4)

andreev551 [17]

PLS HELP ME ASAP I DONT HAVE TIME. IT ALSO DETECTS IF ITs RIGHT OR WRONG. PLS HELP ME ASAP I DONT HAVE TIME. IT ALSO DETECTS IF ITs RIGHT OR WRONG.

4 0

3 years ago

1, 5, 17, 53, ... Use inductive reasoning to create a general rule for the sequence. A. Multiply by 3, then add 2. B. Multiply b

Basile [38]

The answer to this problem is the letter "A" which is "Multiply by 3, then add 2"
and can be written a N = 3n + 2
At first, we have initial value such n = 1
Then the second value is:
N = 3*1 + 2
N = 5
The third value is:
N = 3*5 + 2
N=17
The next values are:
N = 3*17 + 2
N= 53
The letter "A" is the inductive reasoning to the given sequence.

6 0

3 years ago