What percent of 30 is 13

Mathematics

1 answer:

Rom4ik [11]3 years ago

8 0

Answer:3.9

Step-by-step explanation:

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What is the answer to

gavmur [86]

Answer:

y = 3/4x+7

Step-by-step explanation:

The slope is 3/4 and a point is (-8,1)

We can use point slope to make an equation for the line

y-y1 = m(x-x1)

y-1 = 3/4(x--8)

y-1 = 3/4(x+8)

y-1 = 3/4x +6

Add 1 to each side

y-1+1 = 3/4 x+6+1

y = 3/4x+7

This is in slope intercept form (y=mx+b)

7 0

3 years ago

Repeated student samples. Of all freshman at a large college, 16% made the dean’s list in the current year. As part of a class p

Dima020 [189]

Answer:

a) p-hat (sampling distribution of sample proportions)

b) Symmetric

c) σ=0.058

d) Standard error

e) If we increase the sample size from 40 to 90 students, the standard error becomes two thirds of the previous standard error (se=0.667).

Step-by-step explanation:

a) This distribution is called the <em>sampling distribution of sample proportions</em> <em>(p-hat)</em>.

b) The shape of this distribution is expected to somewhat normal, symmetrical and centered around 16%.

This happens because the expected sample proportion is 0.16. Some samples will have a proportion over 0.16 and others below, but the most of them will be around the population mean. In other words, the sample proportions is a non-biased estimator of the population proportion.

c) The variability of this distribution, represented by the standard error, is:

$\sigma=\sqrt{p(1-p)/n}=\sqrt{0.16*0.84/40}=0.058$

d) The formal name is Standard error.

e) If we divided the variability of the distribution with sample size n=90 to the variability of the distribution with sample size n=40, we have:

$\frac{\sigma_{90}}{\sigma_{40}}=\frac{\sqrt{p(1-p)/n_{90}} }{\sqrt{p(1-p)/n_{40}}}}= \sqrt{\frac{1/n_{90}}{1/n_{40}}}=\sqrt{\frac{1/90}{1/40}}=\sqrt{0.444}= 0.667$