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stiks02 [169]
3 years ago
9

What is the equation of a circle centered at (1,-4) and a diameter 18?

Mathematics
2 answers:
hoa [83]3 years ago
7 0

Answer:

(x - 1)² + (y + 4)² = 81

Step-by-step explanation:

Circle Formula: (x - h)² + (y - k)² = r²

(h, k) is the center

2r = d

Step 1: Find <em>r</em>

18 = 2r

r = 9

Step 2: Plug known variables into formula

(x - 1)² + (y + 4)² = 9²

Step 3: Evaluate

(x - 1)² + (y + 4)² = 81

jonny [76]3 years ago
7 0

Answer:

(x-1)^2 + (y+4)^2 = 81

Step-by-step explanation:

The equation of a circle can be written as

(x-h)^2 + (y-k)^2 = r^2

where ( h,k) is the center and r is the radius

The center is ( 1,-4)

and the radius is d/2 = 18/2 = 9

(x-1)^2 + (y- -4)^2 = 9^2

(x-1)^2 + (y+4)^2 = 81

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The International Air Transport Association surveys business travelers to develop quality ratings for transatlantic gateway airp
motikmotik

Answer:

The 95% confidence interval for the population mean rating is (5.73, 6.95).

Step-by-step explanation:

We start by calculating the mean and standard deviation of the sample:

M=\dfrac{1}{n}\sum_{i=1}^n\,x_i\\\\\\M=\dfrac{1}{50}(6+4+6+. . .+6)\\\\\\M=\dfrac{317}{50}\\\\\\M=6.34\\\\\\s=\sqrt{\dfrac{1}{n-1}\sum_{i=1}^n\,(x_i-M)^2}\\\\\\s=\sqrt{\dfrac{1}{49}((6-6.34)^2+(4-6.34)^2+(6-6.34)^2+. . . +(6-6.34)^2)}\\\\\\s=\sqrt{\dfrac{229.22}{49}}\\\\\\s=\sqrt{4.68}=2.16\\\\\\

We have to calculate a 95% confidence interval for the mean.

The population standard deviation is not known, so we have to estimate it from the sample standard deviation and use a t-students distribution to calculate the critical value.

The sample mean is M=6.34.

The sample size is N=50.

When σ is not known, s divided by the square root of N is used as an estimate of σM:

s_M=\dfrac{s}{\sqrt{N}}=\dfrac{2.16}{\sqrt{50}}=\dfrac{2.16}{7.071}=0.305

The degrees of freedom for this sample size are:

df=n-1=50-1=49

The t-value for a 95% confidence interval and 49 degrees of freedom is t=2.01.

The margin of error (MOE) can be calculated as:

MOE=t\cdot s_M=2.01 \cdot 0.305=0.61

Then, the lower and upper bounds of the confidence interval are:

LL=M-t \cdot s_M = 6.34-0.61=5.73\\\\UL=M+t \cdot s_M = 6.34+0.61=6.95

The 95% confidence interval for the mean is (5.73, 6.95).

4 0
3 years ago
What is the slope the line?
laila [671]

Answer:

the slope is 3/4x

Step-by-step explanation:

if you need it in slope intercept form too its y=3/4x-1

4 0
3 years ago
Ariel made cupcakes to sell. 2/3 of them were chocolate chip,25% of the reminder was strawberry and the rest were 90 vanilla cup
Anton [14]

Answer:

Let x be the total number of cupcakes.

Chocolate chips =

\frac{2}{3} x

Strawberry =

\frac{1}{4}  \times  \frac{1}{3}  \\  =  \frac{1}{12} x

Vanilla =

x -  \frac{2}{3} x -  \frac{1}{12}x \\  =  \frac{1}{3} x -  \frac{1}{12} x \\   =  \frac{1}{4} x

given

\frac{1}{4} x = 90

x = 90 \div  \frac{1}{4}  \\  = 90 \times 4 \\  = 360

a)Number of Chocolate chip Cupcakes =

\frac{2}{3}  \times 360 \\  = 240

b)Number of Strawberry cupcakes =

\frac{1}{12}  \times 360 \\  = 30

8 0
3 years ago
Help me with this problem
omeli [17]
Add -3.4 to both sides
-9.3 = y
Hope this helps!
4 0
3 years ago
How do I find X when the triangle is a right angle?
qwelly [4]

1:Replace the variables in the theorem with the values of the known sides.

2:Square the measures, and subtract from each side

3: find the square root of each side

6 0
3 years ago
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