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3 years ago

the diameter of the sphere is 7 inches. What is the circumference of a cross section through the center of the model?

Mathematics

1 answer:

Lerok [7]3 years ago

3 0

Answer:

Step-by-step explanation:

Circumference is 2r × Pi. Circumference of half is 2r × Pi / 2

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If the 32 ounce bottle is 20% more than the typical bottle, how many ounces are in the typical bottle? Round your answer to the

Elenna [48]

6.4 %. hope that helped

4 0

3 years ago

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What type of plate boundary is illustrated in the image?

viktelen [127]

Haha wring subject but convergent

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3 years ago

The following equation describes a circle.

Simora [160]

Answer:

Center = (5, -2) and radius = √33

Step-by-step explanation:

The equation of a circle is given by the formula;

(x-a)² + (y-b)² = r² ; where (a,b) is the center of the circle and r is the radius of the circle.

In this case;

2x² - 20x + 2y² + 8y =40 ;

Dividing both sides of the equation by 2 we get;

x² - 10x + y² + 4y = 20

we can then use the completing the square on both x and y terms.

x² - 10x + y² + 4y = 20

x² + 2(-5)x + 25 + y² + 2(2) y + 4 = 20 +9 + 4

In standard form we get;

(x-5)² + (y+2)² = 33

Therefore;

Center = (5, -2) and radius = √33

3 0

3 years ago

When a = a or 2 = 2, what type of solution do we have

Ilia_Sergeevich [38]

Answer:

Step-by-step explanation:

a = a (true)

2 = 2 (true)

6 0

3 years ago

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Location is known to affect the number, of a particular item, sold by an auto parts facility. Two different locations, A and B,

Mama L [17]

We have two samples, A and B, so we need to construct a 2 Samp T Int using this formula:

$\displaystyle \overline {x}_1 - \overline {x}_2 \ \pm \ t^{*} \sqrt{\frac{s_1^2}{n_1} + \frac{s_2^2}{n_2} }$

In order to use t*, we need to check conditions for using a t-distribution first.

Random for both samples -- NOT STATED in the problem ∴ proceed with caution!
Independence for both samples: 130 < all items sold at Location A; 180 < all items sold at Location B -- we can reasonably assume this is true
Normality: CLT is not met; n < 30 for both locations A and B ∴ proceed with caution!

Since 2/3 conditions aren't met, we can still proceed with the problem but keep in mind that the results will not be as accurate until more data is collected or more information is given in the problem.

Solve for t*:

We need the tail area first.

$\displaystyle \frac{1-.9}{2}= .05$

Next we need the degree of freedom.

The degree of freedom can be found by subtracting the degree of freedom for A and B.

The general formula is df = n - 1.

df for A: 13 - 1 = 12
df for B: 18 - 1 = 17
df for A - B: |12 - 17| = 5

Use a calculator or a t-table to find the corresponding t-score for df = 5 and tail area = .05.

t* = -2.015

Now we can use the formula at the very top to construct a confidence interval for two sample means.

$\overline {x}_A=39$
$s_A=8$
$n_A=13$
$\overline {x}_B = 55$
$s_B=2$
$n_B=18$
$t^{*}=-2.015$

Substitute the variables into the formula: $\displaystyle \overline {x}_1 - \overline {x}_2 \ \pm \ t^{*} \sqrt{\frac{s_1^2}{n_1} + \frac{s_2^2}{n_2} }$ .

$39-55 \ \pm \ -2.015 \big{(}\sqrt{\frac{(8)^2}{13} +\frac{(2)^2}{18} } } \ \big{)}$

Simplify this expression.

$-16 \ \pm \ -2.015 (\sqrt{5.1453} \ )$
$-16 \ \pm \ 3.73139$

Adding and subtracting 3.73139 to and from -16 gives us a confidence interval of:

$(-20.5707,-11.4293)$

If we want to interpret the confidence interval of (-20.5707, -11.4293), we can say...

We are 90% confident that the interval from -20.5707 to -11.4293 holds the true mean of items sold at locations A and B.

5 0

1 year ago