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3 years ago

8

Last year, the city library collected 117 used books for its shelves.This year, it collected 3 times as many books. How many boo

ks did it collect this year?

1 answer:

andrezito [222]3 years ago

5 0

They collected 351 books this year

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Ayo i need help this is vv hard or i’m jus dumb.

erastovalidia [21]

It goes straight up I hope this helps if not in sorry

4 0

2 years ago

a major metroplitan newspaper selected a simple random sample of 1,600 readers from their list of 100,000 subscribers. they aske

Arisa [49]

Answer:

The 99% confidence interval for the proportion of readers who would like more coverage of local news is (0.3685, 0.4315).

Step-by-step explanation:

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:

$n = 1600, \pi = 0.4$

99% confidence level

So $\alpha = 0.01$ , z is the value of Z that has a pvalue of $1 - \frac{0.01}{2} = 0.995$ , so $Z = 2.575$ .

The lower limit of this interval is:

$\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.4 - 2.575\sqrt{\frac{0.4*0.6}{1600}} = 0.3685$

The upper limit of this interval is:

$\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.4 + 2.575\sqrt{\frac{0.4*0.6}{1600}} = 0.4315$

The 99% confidence interval for the proportion of readers who would like more coverage of local news is (0.3685, 0.4315).

7 0

2 years ago

There are 4 boys and 2 girls from the seventh grade and 3 boys and 5 girls from the eighth grade in the math club. The math club

inna [77]

Answer:

5/24 or 20.8%

Step-by-step explanation:

Probability that the 7th grader is a boy = number of boys/(total kids) = 4/(4+4) = 1/2

Probability that the 8th grader is a boy = 5/(5+7) = 5/12

Probability that both are boys = 1/2*(5/12) = 5/24 or 20.8%

7 0

2 years ago

Which equation has 1 solution?<br><br> IwI = -2<br> IwI = -1<br> IwI = 0<br> IwI = - 1

vovangra [49]

Absolute value is alwas positive
so all of them excet the 3rd one are false

|w|=0 has 1 solution

if the last one was |w|=1 then ther would be 2 solutions, -1 and 1

answer is |w|=0

6 0

2 years ago

Determine the domain of the function, and then graph it.

Tomtit [17]

First set change the function f(x) to y so
that it would be
$y = \sqrt{x + 4} - 1$
Then set y = 0
$0 = \sqrt{x + 4} - 1$
Then solve for x

X = - 3

To graph it, just plot the point (-3,0) on the x-axis

6 0

2 years ago