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3 years ago

15

Solve everything for brainiest

1 answer:

IRISSAK [1]3 years ago

6 0

Answer:

1. $a = 8$

2. $b = \frac{1}{8}$

3. $c = 2 \frac{3}{5}$

4. $d = \frac{13}{50}$

Step-by-step explanation:

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-1/4 [p+16]=2 help me pls

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Answer:

6p

Step-by-step explanation:

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3 years ago

Y=2-4× calculate slope

Nezavi [6.7K]

Answer:

the slope is -4. it can also be seen as -4/1

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3 years ago

Solve the problem. The systolic blood pressures of the patients at a hospital are normally distributed with a mean of 136mm Hg a

Maru [420]

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</span>I think this is the answer but I'm not sure.

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3 years ago

165 Students went on a filed trip. three buses were filled and 21 students traveled in cars. how many students were in each bus?

andrew-mc [135]

Answer:

48 students in each bus

Step-by-step explanation:

5 0

3 years ago

A sociologist wishes to estimate the percentage of the United States population living in poverty. What size sample should be ob

andriy [413]

Answer:

a) We need a sample size of at least 705.

b) We need a sample size of at least 1692.

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 $1 - \frac{\alpha}{2}$ .

The margin of error is:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

90% confidence level

So $\alpha = 0.1$ , z is the value of Z that has a pvalue of $1 - \frac{0.1}{2} = 0.95$ , so $Z = 1.645$ .

a) If she uses 1999 estimate of 11.8% obtained from the Current Population Survey.

We need a sample of size at least n

n is found when $M = 0.02, \pi = 0.118$ .

So

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.02 = 1.645\sqrt{\frac{0.118*0.882}{n}}$

$0.02\sqrt{n} = 1.645\sqrt{0.118*0.882}$

$\sqrt{n} = \frac{1.645\sqrt{0.118*0.882}}{0.02}$

$(\sqrt{n})^{2} = (\frac{1.645\sqrt{0.118*0.882}}{0.02})^{2}$

$n = 704.08$

Rounding up

We need a sample size of at least 705.

b) She does not use any estimate.

Same thing as above, we just use $\pi = 0.5$ when do not use any estimate.

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.02 = 1.645\sqrt{\frac{0.5*0.5}{n}}$

$0.02\sqrt{n} = 1.645\sqrt{0.5*0.5}$

$\sqrt{n} = \frac{1.645\sqrt{0.5*0.5}}{0.02}$

$(\sqrt{n})^{2} = (\frac{1.645\sqrt{0.5*0.5}}{0.02})^{2}$

$n = 1691.2$

Rounding up

We need a sample size of at least 1692.

4 0

3 years ago