4. Find the percent of increase from 56 to 70. Round your answer

In a simple random sample of 14001400 young people, 9090% had earned a high school diploma. Complete parts a through d below.

ratelena [41]

Answer:

(a) The standard error is 0.0080.

(b) The margin of error is 1.6%.

(c) The 95% confidence interval for the percentage of all young people who earned a high school diploma is (88.4%, 91.6%).

(d) The percentage of young people who earn high school diplomas has increased.

Step-by-step explanation:

Let p = proportion of young people who had earned a high school diploma.

A sample of n = 1400 young people are selected.

The sample proportion of young people who had earned a high school diploma is:

$\hat p=0.90$

(a)

The standard error for the estimate of the percentage of all young people who earned a high school diploma is given by:

$SE_{\hat p}=\sqrt{\frac{\hat p(1-\hat p)}{n}}$

Compute the standard error value as follows:

$SE_{\hat p}=\sqrt{\frac{\hat p(1-\hat p)}{n}}$

$=\sqrt{\frac{0.90(1-0.90)}{1400}}\\$

$=0.008$

Thus, the standard error for the estimate of the percentage of all young people who earned a high school diploma is 0.0080.

(b)

The margin of error for (1 - α)% confidence interval for population proportion is:

$MOE=z_{\alpha/2}\times SE_{\hat p}$

Compute the critical value of z for 95% confidence level as follows:

$z_{\alpha/2}=z_{0.05/2}=z_{0.025}=1.96$

Compute the margin of error as follows:

$MOE=z_{\alpha/2}\times SE_{\hat p}$

$=1.96\times 0.0080\\=0.01568\\\approx1.6\%$

Thus, the margin of error is 1.6%.

(c)

Compute the 95% confidence interval for population proportion as follows:

$CI=\hat p\pm MOE\\=0.90\pm 0.016\\=(0.884, 0.916)\\\approx (88.4\%,\ 91.6\%)$

Thus, the 95% confidence interval for the percentage of all young people who earned a high school diploma is (88.4%, 91.6%).

(d)

To test whether the percentage of young people who earn high school diplomas has increased, the hypothesis is defined as:

H₀: The percentage of young people who earn high school diplomas has not increased, i.e. p = 0.80.

Hₐ: The percentage of young people who earn high school diplomas has not increased, i.e. p > 0.80.

Decision rule:

If the 95% confidence interval for proportions consists the null value, i.e. 0.80, then the null hypothesis will not be rejected and vice-versa.

The 95% confidence interval for the percentage of all young people who earned a high school diploma is (88.4%, 91.6%).

The confidence interval does not consist the null value of p, i.e. 0.80.

Thus, the null hypothesis is rejected.

Hence, it can be concluded that the percentage of young people who earn high school diplomas has increased.

8 0

3 years ago

A car is moving at a speed of 50 km/hour. The driver takes her foot off of the accelerator and the car coasts to a stop. Why? A)

velikii [3]

C) without an external energy source, fiction stops the car

Sure hope this helps you

4 0

2 years ago

Read 2 more answers

Peter is the owner of a hotel. He has found that when he charges the nightly cost of $139, the average occupancy is 275. In addi

zimovet [89]

Answer:

Without price increase, Cost/night = $119

Average occupancy = 372 The revenue will be 119*372 = $44,268

For every $15 price increase, the occupancy decreases by 25. Therefore with x price increases, The revenue will be $(119 + 15x)*(372 25x)

Cost/night = $119 + 15x Occupancy = 372 - 25x

Answer:

The nightly cost with x $15 price increases is $119 + 15x.

3 0

2 years ago

This equation shows how the accuracy of Alexa's watch is related to how long it's been since she last set it.

Kruka [31]

Answer:

2

Step-by-step explanantion:

You sustitute 20 for s to get 20 = d + 18, subtract 18 from both sides and you get d = 2.

4 0

3 years ago

Please help me 7.2 × 2.1

Varvara68 [4.7K]

Answer:

15.12

Step-by-step explanation:

That's the a water to ur question.

hope it helps.

Have a good day and stay safe!

5 0

3 years ago

Read 2 more answers