If the original price was $58 and the new price is $66 what is the percent change

A newsgroup is interested in constructing a 90% confidence interval for the proportion of all Americans who are in favor of a ne

Leto [7]

Answer:

The 90% confidence interval for the proportion of all Americans who are in favor of a new Green initiative is (0.6247, 0.6923).

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 $1 - \frac{\alpha}{2}$ .

Of the 533 randomly selected Americans surveyed, 351 were in favor of the initiative.

This means that $n = 533, \pi = \frac{351}{533} = 0.6585$

90% confidence level

So $\alpha = 0.1$ , z is the value of Z that has a p-value of $1 - \frac{0.1}{2} = 0.95$ , so $Z = 1.645$ .

The lower limit of this interval is:

$\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.6585 - 1.645\sqrt{\frac{0.6585*0.3415}{533}} = 0.6247$

The upper limit of this interval is:

$\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.6585 + 1.645\sqrt{\frac{0.6585*0.3415}{533}} = 0.6923$

The 90% confidence interval for the proportion of all Americans who are in favor of a new Green initiative is (0.6247, 0.6923).

6 0

3 years ago

Triangle XYZ was dilated by a scale factor of 2 to create triangle ACB and cos ∠X = 2 and 5 tenths over 5 and 59 hundredths.

Maru [420]

Based on the above, the Triangle XYZ and ACB are known to be similar triangles since tanX = tanA = 5 over 2 and 5 tenths;

Hence:

AC = 2 x XY
CB = 2 x YZ

<h3>What is the triangle about?</h3>

From the question given; Triangle XYZ is known to have been dilated by a scale factor of 2 to form a type of triangle known as triangle ACB, So therefore, XYZ and ACB are known to be the same or similar triangles.

Since Angles Y and C are known to both measure 90 degrees, and angles A and X are said to be congruent. Therefore:

tanX = tanA = 5 over 2 and 5 tenths

AC = 2 x XY

CB = 2 x YZ

For part B:

cosX=Base/Hypotenuse

cos A=AC/AB

AC = 2.05

AB = 5.59

Therefore, Based on the above, the Triangle XYZ and ACB are known to be similar triangles since tanX = tanA = 5 over 2 and 5 tenths;

Hence: