Help Wegnerkolmp2741o i need ur help!

Amy is using a drawing program to complete a construction with which she is almost finished. Which construction is she completin

AlexFokin [52]

Amy is constructing an equilateral triangle. it's she joins the centers of the 2 circles to the point of intersection she will be done

option a

8 0

4 years ago

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hi PLLSS HELP solve x2 – 8x = 20 by completing the square. Which is the solution set of the equation? {–22, 14} {–14, 22} {–10,

Anuta_ua [19.1K]

Answer:

{ - 2, 10 }

Step-by-step explanation:

Given

x² - 8x = 20

To complete the square

add ( half the coefficient of the x- term )² to both sides

x² + 2(- 4)x + 16 = 20 + 16, that is

(x - 4)² = 36 ( take the square root of both sides )

x - 4 = ± $\sqrt{36}$ = ± 6 ( add 4 to both sides )

x = 4 ± 6

Thus

x = 4 - 6 = - 2

x = 4 + 6 = 10

3 0

3 years ago

Of the total population of the United States, 20% live in the northeast. If 200 residents of the United States are selected at r

Snezhnost [94]

Answer:

0.0465 = 4.65% probability that at least 50 live in the northeast.

Step-by-step explanation:

I am going to use the normal approximation to the binomial to solve this question.

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

Can be approximated to a normal distribution, using the expected value and the standard deviation.

The expected value of the binomial distribution is:

$E(X) = np$

The standard deviation of the binomial distribution is:

$\sqrt{V(X)} = \sqrt{np(1-p)}$

Normal probability distribution

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

When we are approximating a binomial distribution to a normal one, we have that $\mu = E(X)$ , $\sigma = \sqrt{V(X)}$ .