What is the value of the expression? −4.2 (0.35−3.5)

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

Uma is paid $12.25 for each chair she decorates. Last week she

Luda [366]

Answer:

$514.50

Step-by-step explanation:

7+4+2+8=21

$12.25x21=$514.50

6 0

3 years ago

Calculate the distance between the points M(6,2) and N(-1,7).

raketka [301]

Answer: chupapi munanyo

Step-by-step explanation:chupapi munanyo

8 0

3 years ago

How can you analyze the numerator and/or the denominator in a rational expression to locate the x-intercepts?

andre [41]

Answer:

$x=0$ for $f(x)=\frac{P(x)}{Q(x)}$ , with $Q(x) \neq 0$ .

Step-by-step explanation:

To obtain x-intercepts, we need to give certain value, specifically $x=0$ .

However, in case of a rational function, we must make sure that $x=0$ doesn't makes the denominator null, beacuse in that case the function is undefined.

Therefore, for x-intercepts we must say

$x=0$ for $f(x)=\frac{P(x)}{Q(x)}$ , with $Q(x) \neq 0$ .

7 0

3 years ago

The ratio of art class to music class is 4:3. If there is 8 more students in art class, how many students are in music class

pishuonlain [190]

Answer:

9 students in music class.

Step-by-step explanation:

In art there are 4 and since there are 8 more 8 + 4 = 12. so there are 12 in Art.

4 x _ = 12. —> 4 x 3 = 12.
so we need to do the same for music class.

For music there are 3.
so we multiply by 3 like we did with the 4.

3 x 3 = _ —> 3 x 3 =9.
so there are 9 students in music class.

6 0

2 years ago