Please help ASAP please!!!

What is the center of the circle having the equation (x – 7)2 + (y + 2)2 = 121? What is the radius?

Sholpan [36]

The standard equation of a circle with center (h, k) and radius : r
is (x - h)² + (y - k)² = r².
h=7 k = -2 r = 11
the center is ( 7, -2) and radius 11

5 0

4 years ago

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The Empire State Building in New York City

Andreyy89

D
Because the height of the Eiffel Tower would need to be 119.2 meters taller to be 443.2 meters tall

8 0

3 years ago

I need to understand this kindly help.....

AveGali [126]

Answer:

Section a)

Solution;

A correlation coefficient of 0.4 implies a relatively weak positive association between two sets of data. There is a notable small increment in one data set as the other increases.

Section b)

Solution;

A correlation coefficient of -0.96 implies a strong negative association between two sets of data. An increase in the values of one data set amounts to a decrease in the values of the other data set by approximately the same magnitude.

Section c)

Solution;

A correlation coefficient of -0.02 implies a weak negative association between two sets of data. An increase in the values of one data set amounts to a negligible decrease in the values of the other data set.

Section d)

Solution;

A correlation coefficient of 1.0 implies a perfect positive association between two sets of data. An increase in the values of one data set amounts to an increase in the values of the other data set by exactly the same magnitude. A scatter plot would reveal that the line y =x fits the data well.

Section e)

Solution;

A correlation coefficient of 0.86 implies a strong positive association between two sets of data. An increase in the values of one data set amounts to an increase in the values of the other data set by approximately the same magnitude.

Step-by-step explanation:

Correlation coefficient measures the degree of association between two variables or data sets. Correlation coefficients can be positive or negative and may imply weak or strong association between two data sets.

A correlation coefficient of less than 5 is implies a weak association while a value greater than or equal to 5 implies a strong association. Finally, a correlation of 1.0 implies perfect association.

7 0

3 years ago

What is the correct decimal expansion of 52? A) 52 B) 0.25 C) 5.20

Bas_tet [7]

Answer:

A

Step-by-step explanation:

52 is a whole number so the other answers are wrong because they are not whole numbers and less than 52.

8 0

3 years ago

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Of the total population of American households, including older Americans and perhaps some not so old, 17.3% receive retirement

Alex Ar [27]

Answer:

47.54% probability that more than 20 households but fewer than 35 households receive a retirement income

Step-by-step explanation:

We use the binomial aproxiation to the normal 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 $\mu = E(X)$ , $\sigma = \sqrt{V(X)}$ .

In this problem, we have that:

$p = 0.173, n = 120$ . So

$\mu = E(X) = np = 120*0.173 = 20.76$

$\sigma = \sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{120*0.173*0.827} = 4.14$

In a random sample of 120 households, what is the probability that more than 20 households but fewer than 35 households receive a retirement income?

We are working with discrete values, so this is the pvalue of Z when X = 35-1 = 34 subtracted by the pvalue of Z when X = 20 + 1 = 21.

X = 34

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

$Z = \frac{34 - 20.76}{4.14}$