The 99% confidence interval for the proportion of all American adults who blame Barack Obama a great deal or a moderate amount for U.S. economic problems is (0.4894, 0.5706)..

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 zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

For this problem, we have that:

$n = 1004, \pi = 0.53$

99% confidence level

So $\alpha = 0.01$ , z is the value of Z that has a pvalue of $1 - \frac{0.01}{2} = 0.995$ , so $Z = 2.575$ .

The lower limit of this interval is:

$\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.53 - 2.575\sqrt{\frac{0.53*0.47}{1004}} = 0.4894$

The upper limit of this interval is:

$\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.53 - 2.575\sqrt{\frac{0.53*0.47}{1004}} = 0.5706$

The 99% confidence interval for the proportion of all American adults who blame Barack Obama a great deal or a moderate amount for U.S. economic problems is (0.4894, 0.5706)..

3 0

2 years ago

The black graph is the graph of y=f(x). Choose the equation for the red graph.<br> Please help me!!!

dusya [7]

Answer:

Step-by-step explanation:

The red graph is a horizontal translation of 5 units left followed by a reflection in the x- axis.

Given f(x) then f(x + a) is a horizontal translation of f(x)

• If a > 0 then a shift to the left of a units

• If a < 0 then a shift to the right of a units

The black graph is shifted 5 units left, thus

f(x) → f(x + 5)

Under a reflection in the x- axis

a point (x, y ) → (x, - y )

Note that the y- coordinate of the image is the negative of the original

Note also that $\frac{y}{-1}$ = - y, thus

$\frac{y}{-1}$ = f(x + 5) → B

5 0

3 years ago

Read 2 more answers

Which equation is equivalent to 2 1/4+2/4=2 3/4?

IceJOKER [234]

Answer:

11/4

Step-by-step explanation:

8 0

3 years ago