When a number is divided by -3, the result is 12 more than the number. What is the number?

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

2 years ago

if 3 buckets containing 2kg of paint has been used to paint a fence 90 m long and 80 cm high. how many buckets of 2kg of paint a

Anit [1.1K]

3 buckets covers 90m x 80cm = 3 buckets for 90x0.8 = 3 for 72

x buckets covers 200m x 120cm = x buckets for 200x1.2 = x for 240

3/72 = x/240
720 = 72x
x =10 buckets of paint to cover 200mx120cm fence

8 0

2 years ago

45% of what number is 27?

gtnhenbr [62]

45% of what number is 27

0.45x = 27
x = 27 / 0.45
x = 60 <== 45% of 60 = 27

5 0

3 years ago

Jill Kingman pays a $419.00 premium annually. This represents 35% of the total premium. The rest of the premium is paid by her e

Leto [7]

Answer:

I think the answer is 1,466.50

8 0

3 years ago

The model represents an equation. What value of x makes the equation true?

goldfiish [28.3K]

Answer:

A. 2.25

Step-by-step explanation:

-3x + 10 = 5x - 8 (Given)

10 = 8x - 8 (Added 3x on both sides)

18 = 8x (Added 8 on both sides)

2.25 = x (Divided 8 on both sides)

4 0

3 years ago