All categories

3 years ago

A. 1

Mathematics

1 answer:

dimulka [17.4K]3 years ago

7 0

Step-by-step explanation:

Given equation of circle (in general form) is:

$8 {x}^{2} + 8 {y}^{2} - 16x - 32y + 24 = 0 \\ \\ dividing \: throughout \: by \: 8 \: we \: find : \\ {x}^{2} + {y}^{2} - 2x - 4y + 3 = 0 \\ equating \: it \: with : \\ {x}^{2} + {y}^{2} + 2gx + 2fy + c = 0 \\ 2g = - 2 \implies \: g = - 1\\ 2f = - 4 \implies \: f = - 2 \\ c = 3 \\ \therefore \:center = ( - g, \: \: - f) = (1, \: \: 2) \\ \\ radius \: r = \sqrt{ {g}^{2} + {f}^{2} - c } \\ = \sqrt{ {1}^{2} + {2}^{2} - 3} \\ = \sqrt{1 + 4 - 3} \\ = \sqrt{5 - 3} \\ = \sqrt{2} \: units$

You might be interested in

De las siguientes relaciones entre dos variables, razona cuáles son funcionales y cuáles no: a. Edad – altura de la persona a lo

Arte-miy333 [17]

Answer:

In this problem, we need to describe the relation between variables, if that relation is functional or not. It's important to say that we assumed that the first variable is independent, and the second is dependent.

Age - Height of the person along his life: These variable are functinal and make total sense, because through time the person grows, which means the height changes as the age increases. These variables have a proportional relationship.

Height - Age of the person: These relation is not functional, becasuse age can't be a dependent variable, beacuse the age of a person doesn't depends on his height.

Gasoline price - Day of the Month: These relation is not functional, becasue time must be the independent variable.

Day of the Month - Gasoline price: These realation make sense, beacuse the price of the gasoline can be depedent of the day of the month.

A number and its fifth part: Notice that the fifth part depends on the number, it's defined by it, so this can be a function.

A number and its square root: These two variables represent a function, where "a number" represents the domain value and "its square root" represents a range vale.

4 0

3 years ago

Suppose that the national average for the math portion of the College Board's SAT is 515. The College Board periodically rescale

nasty-shy [4]

Answer:

a) 16% of students have an SAT math score greater than 615.

b) 2.5% of students have an SAT math score greater than 715.

c) 34% of students have an SAT math score between 415 and 515.

d) $Z = 1.05$

e) $Z = -1.10$

Step-by-step explanation:

To solve this question, we have to understand the normal probability distribution and the empirical rule.

Normal probability distribution

Problems of normally distributed samples are 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.

Empirical rule

The Empirical Rule states that, for a normally distributed random variable:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviation of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

$\mu = 515, \sigma = 100$

(a) What percentage of students have an SAT math score greater than 615?

615 is one standard deviation above the mean.

68% of the measures are within 1 standard deviation of the mean. The other 32% are more than 1 standard deviation from the mean. The normal probability distribution is symmetric. So of those 32%, 16% are more than 1 standard deviation above the mean and 16% more then 1 standard deviation below the mean.

So, 16% of students have an SAT math score greater than 615.

(b) What percentage of students have an SAT math score greater than 715?

715 is two standard deviations above the mean.

95% of the measures are within 2 standard deviations of the mean. The other 5% are more than 2 standard deviations from the mean. The normal probability distribution is symmetric. So of those 5%, 2.5% are more than 2 standard deviations above the mean and 2.5% more then 2 standard deviations below the mean.

So, 2.5% of students have an SAT math score greater than 715.

(c) What percentage of students have an SAT math score between 415 and 515?

415 is one standard deviation below the mean.

515 is the mean

68% of the measures are within 1 standard deviation of the mean. The normal probability distribution is symmetric, which means that of these 68%, 34% are within 1 standard deviation below the mean and the mean, and 34% are within the mean and 1 standard deviation above the mean.

So, 34% of students have an SAT math score between 415 and 515.

(d) What is the z-score for student with an SAT math score of 620?

We have that:

$\mu = 515, \sigma = 100$

This is Z when X = 620. So

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

$Z = \frac{620 - 515}{100}$

$Z = 1.05$

(e) What is the z-score for a student with an SAT math score of 405?

We have that:

$\mu = 515, \sigma = 100$

This is Z when X = 405. So

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

$Z = \frac{405 - 515}{100}$

$Z = -1.10$

3 0

4 years ago

What are the values of x and y

andrey2020 [161]

X is 35 degrees and Y is 70 degrees

3 0

3 years ago

Shelly ran 2 1/4 miles Lynne ran 3 1/8 Miles WhobRan Farther and by how much

ValentinkaMS [17]

Lynne ran farther and by 7/8 miles

You can tell Lynne ran further because she ran 3 whole miles while shelly only ran 2 whole miles. Now you have to subtract to see how much Lynne had ran more.

You found a common denominator between 8 and 4. 4 can turn into 8. so you multiply 4x2 and 1x2 to get a mixed number of 2 2/8

Now you have to turn 3 1/8 because you cannot subtract 2/8 from 1/8. You can turn the fraction into 2 9/8 because there are 8 pieces in a whole.

2 9/8 - 2 2/8 = 0 7/8

Hope this helps! :)

6 0

3 years ago

List the next three numbers for the sequence: 25, 75, 300, 1500, ...

ELEN [110]

Answer: 2000

Step-by-step explanation:

4 0

3 years ago