Please Solve. Thanks.

A pew research Center project on the state of news media showed that the clearest pattern of news audience growth in 2012 came o

KengaRu [80]

Answer:

Step-by-step explanation:

Given that:

the sample proportion p = 0.39

sample size = 100

Then np = 39

Using normal approximation

The sampling distribution from the sample proportion is approximately normal.

Thus, mean $\mu _{\hat p} = p = 0.39$

The standard deviation;

$\sigma = \sqrt{\dfrac{p(1-p)}{n} }$

$\sigma = \sqrt{\dfrac{0.39(1-0.39)}{100} }$

$\sigma = 0.048$

The test statistics can be computed as:

$Z = \dfrac{{\hat _{p}} - \mu_{_ {\hat p}} }{\sigma_{\hat p}}$

$Z = \dfrac{0.3 - 0.39 }{0.0488}$

$Z = -1. 8 4$

From the z - tables;

$P (\hat p \le 0.3 ) = P(z \le -1.84)$

$\mathbf{P (\hat p \le 0.3 ) = 0.0329}$

(b)

Here;

the sample proportion = 0.39

the sample size n = 400

Since np = 400 * 0.39 = 156

Thus, using normal approximation.

From the sample proportion, the sampling distribution is approximate to the mean $\mu_{\hat p} = p = 0.39$

the standard deviation $\sigma_{\hat p} = \sqrt{\dfrac{p(1-p)}{n} }$

$\sigma_{\hat p} = \sqrt{\dfrac{0.39 (1-0.39)}{400} }$

$\sigma_{\hat p} =0.0244$

The test statistics can be computed as:

$Z = \dfrac{{\hat _{p}} - \mu_{_ {\hat p}} }{\sigma_{\hat p}}$

$Z = \dfrac{0.3 - 0.39 }{0.0244}$

$Z = -3.69$

From the z - tables;

$P (\hat p \le 0.3 ) = P(z \le -3.69)$

$\mathbf{P (\hat p \le 0.3 ) = 0.0001}$

(c) The effect of the sample size on the sampling distribution is that:

As sample size builds up, the standard deviation of the sampling distribution decreases.

In addition to that, reduction in the standard deviation resulted in increases in the Z score, and the probability of having a sample proportion that is less than 30% also decreases.

6 0

2 years ago

Someone help me plz !!!!!

Mrac [35]

Answer:

£1 = 25 hits

Step-by-step explanation:

Will get the equation is

$\frac{40}{1000} = \frac{1}{x}$

so, X=25

x = What we want to find

4 0

2 years ago

A 50-foot flagpole is at the entrance of a building that is 300 feet tall. If the length of the flagpole's shadow is 30 feet at

Soloha48 [4]

The equation you can use to solve the problem is;

50/30 = 300/x

Next Cross Multiply

50x = 9000

x = 9000/50

x = 180

The building's shadow is 180 feet tall

7 0

2 years ago

Somebody HELP NOWWW

crimeas [40]

Answer:

y = 1/2x

Step-by-step explanation:

x - 2y = -4

x = -4 + 2y

x + 4 = 2y

2y = x + 4

y = 1/2x + 2

y = 1/2x

5 0

2 years ago

What does -22 belong to

Len [333]

Answer:

it's part of the real number system

it's a rational number

it's an integer

Step-by-step explanation:

6 0

2 years ago