Why do super heroes where their under wear outside

In a random sample of students who took the SAT test, 427 had paid for coaching courses and the remaining 2733 had not. Calculat

Dvinal [7]

Answer:

The 95% confidence interval for the proportion of students who get coaching on the SAT is (0.1232, 0.147).

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the z-score that has a p-value of $1 - \frac{\alpha}{2}$ .

427 had paid for coaching courses and the remaining 2733 had not.

This means that $n = 427 + 2733 = 3160, \pi = \frac{427}{3160} = 0.1351$

95% confidence level

So $\alpha = 0.05$ , z is the value of Z that has a p-value of $1 - \frac{0.05}{2} = 0.975$ , so $Z = 1.96$ .

The lower limit of this interval is:

$\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.1351 - 1.96\sqrt{\frac{0.1351*0.8649}{3160}} = 0.1232$

The upper limit of this interval is:

$\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.1351 + 1.96\sqrt{\frac{0.1351*0.8649}{3160}} = 0.147$

The 95% confidence interval for the proportion of students who get coaching on the SAT is (0.1232, 0.147).

8 0

3 years ago

What is the area of a sector with a central angle of 108 degrees and a diameter of 21.2 cm?

Rasek [7]

Answer:

$105.84\ cm^2$

Step-by-step explanation:

step 1

Find the area of the circle

The area of the circle is

$A=\pi r^{2}$

we have

$r=21.2/2=10.6\ cm$ ----> the radius is half the diameter

substitute

$A=\pi (10.6)^{2}$

$A=112.36\pi\ cm^2$

step 2

Find the area of a sector

Remember that

The area of the circle subtends a central angle of 360 degrees

so

using proportion

Find out the area of a sector with a central angle of 108 degrees

$\frac{112.36\pi}{360^o}=\frac{x}{108^o}\\\\x=112.36\pi(108)/360\\\\x=33.708\pi\ cm^2$

assume

$\pi=3.14$

substitute

$33.708(3.14)=105.84\ cm^2$

7 0

3 years ago

A company paid $72 for 2 cases of printer paper each case contained 12 packages of paper next month the company's office manager

Tems11 [23]

To figure out the cost for 180 packages, you must first calculate how many packages they bought for $72. Since each case holds 12 packages, for $72, the company bought 24 packages (12×2). Then you have to divide 24 into 180 to figure out the cost for those 180 packages and get 7.5. To get the cost of the 180 packages, you must multiply 7.5 (the number of 24 packages that go into 180) by 72 (the cost of one group of 24 packages). You then get 540. The company must pay $540 for the 180 packages.

7 0

2 years ago

On a bird-watching trip, Mei and Jackie counted 68 birds.

defon

Answer:

The answer is 70% if you round it.

Step-by-step explanation:

45 out of 68 is 66 but if you're rounding it the answer is 70%.

5 0

2 years ago

Write an equation of the line passing through point p that is perpendicular to the given line. p(3,1), y=13x−5

Anarel [89]

You know two lines y=ax+b and y=mx+n that are perpendicular, so we have the product a*m=-1

+ This line is perpendicular to y=13x-5, so it has equation: y=-1/13x+b
+ And it passes through the point (3;1), so we have x=3, y=1. So 1=-1/13 *3+b
and b= 1+3/13= 16/13
And we have y=-1/13x+16/13
Have fun

7 0

3 years ago