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2 years ago

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A circle is described by the equation x2 + y2 + 14x + 2y + 14 = 0. What are the coordinates for the center of the circle and the

length of the radius?
A(-7, -1), 36 units
B(7, 1), 36 units
C(7, 1), 6 units
D(-7, -1), 6 units

1 answer:

TiliK225 [7]2 years ago

7 0

Hello :
<span>x² + y² + 14x + 2y + 14 = 0
</span>(x² + 14x) + (y²+ 2y) + 14 = 0
(x² + 14x+49-49) + (y²+ 2y+1-1) + 14 = 0
(x² + 14x+49)-49 + (y²+ 2y+1)-1 + 14 = 0
(x+7)² + (y+1)² =6²...(answer : <span>D(-7, -1), 6 units )</span>

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12,400 x one and one fifth = ________. Will the product of this equation be less than or greater than 12,400? Explain your reaso

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Answer:

Your answer would be 14,880, so it would be greater than 12,400.

12,400 * 1 1/5 = 14,880

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2 years ago

John runs 500 feet per minute. identify the correct conversion factor setup required to compute john's speed in inches per secon

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Answer:

The correct answer is A) 12 Inches/1 Foot multiplied by 60 Seconds /1 Minute

Step-by-step explanation:

The explanation is very direct and simple.

There are 12 Inches in every Foot and 60 seconds in every minute.

This is all that is required to accurately compute johns speed in inches per second.

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2 years ago

Read 2 more answers

A random sample from a normal population is obtained, and the data are given below. Find a 90% confidence interval for . 114 157

melamori03 [73]

Answer:

$103.160 \leq \sigma \leq 187.476$

And the upper bound rounded to the nearest integer would be 187.

Step-by-step explanation:

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 mean or variance 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.

The Chi Square distribution is the distribution of the sum of squared standard normal deviates .

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

$\mu$ population mean (variable of interest)

s represent the sample standard deviation

n represent the sample size

Solution to the problem

Data given: 114 157 203 257 284 299 305 344 378 410 421 450 478 480 512 533 545

The confidence interval for the population variance $\sigma^2$ is given by the following formula:

$\frac{(n-1)s^2}{\chi^2_{\alpha/2}} \leq \sigma \leq \frac{(n-1)s^2}{\chi^2_{1-\alpha/2}}$

On this case we need to find the sample standard deviation with the following formula:

$s=sqrt{\frac{\sum_{i=1}^{17} (x_i -\bar x)^2}{n-1}}$

And in order to find the sample mean we just need to use this formula:

$\bar x =\frac{\sum_{i=1}^n x_i}{n}$

The sample mean obtained on this case is $\bar x= 362.941$ and the deviation s=132.250

The next step would be calculate the critical values. First we need to calculate the degrees of freedom given by:

$df=n-1=17-1=16$

Since the Confidence is 0.90 or 90%, the value of $\alpha=0.1$ and $\alpha/2 =0.05$ , and we can use excel, a calculator or a tabel to find the critical values.

The excel commands would be: "=CHISQ.INV(0.05,16)" "=CHISQ.INV(0.95,16)". so for this case the critical values are:

$\chi^2_{\alpha/2}=26.296$

$\chi^2_{1- \alpha/2}=7.962$

And replacing into the formula for the interval we got:

$\frac{(16)(132.250)^2}{26.296} \leq \sigma \leq \frac{(16)(132.250)^2}{7.962}$

$10641.959 \leq \sigma^2 \leq 35147.074$

Now we just take square root on both sides of the interval and we got:

$103.160 \leq \sigma \leq 187.476$

And the upper bound rounded to the nearest integer would be 187.

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2 years ago

A small cube with side length 6y is placed inside a larger cube with side length 4x^2. What is the difference in the volume of t

fomenos

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List the first five terms of the sequence. a1 = 4, an+1 = 5an − 3

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The recursive formula

$a_{n+1} = 5a_n-3$

is telling you that the next term in the sequence is five times the previous one, minus 3.

So, if we start with $a_1=4$ , we have to multiply it by 5 and subtract 3 to get the next:

$a_2 = 5a_1-3 = 5\cdot 4 - 3 = 20-3 = 17$

And similarly we can obtain all the next terms:

$a_3 = 5a_2-3 = 5\cdot 17 - 3 = 85-3 = 82$

$a_4 = 5a_3-3 = 5\cdot 82 - 3 = 410-3 = 407$

$a_5 = 5a_4-3 = 5\cdot 407 - 3 = 2035-3 = 2032$

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