If n=4, the value of the expression 28-12 + Vn 2 is<br> 15<br> 17<br> 21 helpppppppp

Several years ago, 50% of parents who had children in grades K-12 were satisfied with the quality of education the students r

galina1969 [7]

Answer:

The 95% confidence interval for the proportion of parents that are satisfied with their children's education is (0.4118, 0.4618). 0.5 is not part of the confidence interval, so this represents evidence that parents' attitudes toward the quality of education have changed.

Step-by-step explanation:

We have to see if 50% = 0.5 is part of the confidence interval.

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:

$n = 1095, \pi = \frac{478}{1095} = 0.4365$

95% confidence level

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

The lower limit of this interval is:

$\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.4365 - 1.96\sqrt{\frac{0.4365*0.5635}{1095}} = 0.4118$

The upper limit of this interval is:

$\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.4365 + 1.96\sqrt{\frac{0.4365*0.5635}{1095}} = 0.4612$

The 95% confidence interval for the proportion of parents that are satisfied with their children's education is (0.4118, 0.4618). 0.5 is not part of the confidence interval, so this represents evidence that parents' attitudes toward the quality of education have changed.

5 0

3 years ago

The bells are adding a new room to their house. The room will be a cube with volume 8,000 ft^3. They are going to put in hardwoo

Mandarinka [93]

Answer:

$4000

Step-by-step explanation:

Given that :

Volume of cube = 8000 ft³

Charge per ft² = $10

Recall, volume of a cube = a³

Where a = edge

Hence,

a³ = 8000

Take the cube root of both sides

a = 20

Hence,

Volume = 20 * 20 * 20

The Area of the floor will be :

20 * 20 = 400 ft²

If charge per ft² = $10

400 ft² = ($10 * 400) = $4000

8 0

3 years ago

Y=cosx what will will dy/dx be

aliya0001 [1]

9514 1404 393

Answer:

y' = -sin(x)

Step-by-step explanation:

Your table of derivatives of trig functions tells you the derivative of the cosine is the opposite of the sine.

dy/dx = -sin(x)

6 0

3 years ago

You and your guest have eaten in a restaurant which had excellent service. Your bill comes to $23.00. If you leave exactly a 15%

dem82 [27]

Answer:

23*0.15=$3.45

Step-by-step explanation:

23*0.15=$3.45

3 0

3 years ago

(a^(2) - 25)x = 3a + 15<br> solve for a

trasher [3.6K]

Answer:

Idk I think it is 6....but I could be wrong.

3 0

3 years ago

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If n=4, the value of the expression 28-12 + Vn 2 is 15 17 21 helpppppppp