# 1. The financial aid office of a university asks a sample of students about their employment and earnings. Thereport says that 'for academic year earnings,

###### Question:

with men earning more on the average. No difference (p = 0.476) was found between the earnings of

African-American and white students." Explain both of these conclusions, for the effects of sex and of race on

mean earnings, in language understandable to someone who knows no statistics

## Answers

Hello!

In a normal distribution, between the mean and the mean plus the standar deviation, there is a 34.1% of the data set, between the mean plus the standar deviation, and the mean between two times the standard deviation, there is a 16.2% of the data set, and so on.

If our mean is 16 inches, and the measure is 26 inches, then the difference is 10 inches between them.

a) if the standar deviation is 2 inches, then you are 10/2 = 5 standar deviations from the mean.

b) yes, is really far away from the mean, in a normal distribution a displacement of 5 standar deviations has a very small probability.

c) Now the standar deviation is 7, so now 26 is in the range between 1 standar deviation and 2 standar deviations away from the mean.

Then this you have a 16% of the data, then in this case, 26 inches is not far away from the mean.

a) 25 is 3 standard deviation from the mean

b) Is far away from the mean, only 0,3 % away from the right tail

c) 25 is pretty close to the mean (just a little farther from 1 standard deviation)

Step-by-step explanation:

We have a Normal Distribution with mean 16 in.

Case a) we also have a standard deviation of 3 inches

3* 3 = 9

16 (the mean) plus 3*σ equal 25 in. the evaluated value, then the value is 3 standard deviation from the mean

Case b) 25 is in the range of 99,7 % of all value, we can say that value is far away from the mean, considering that is only 0,3 % away from the right tail

Case c) If the standard deviation is 7 then

mean + 1*σ = 16 + 7 =23

25> 23

25 is pretty close to the mean only something more than 1 standard deviation

a) 3 standard deviations above 16

b) More than 2 standard deviations of the mean, so yes, 22 inches is faw away from the mean of 16 inches.

c) Less than 2 standard deviations, so not far away.

Step-by-step explanation:

Z-score:

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

If Z < -2 or Z > 2, X is considered to be far away from the mean.

In this question, we have that:

[tex]\mu = 16[/tex]

(a) Suppose the data come from a sample whose standard deviation is 2 inches. How many standard deviations is 22 inches from 16 inches?

This is Z when [tex]X = 22, \sigma = 2[/tex].

So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{22 - 16}{2}[/tex]

[tex]Z = 3[/tex]

So 22 inches is 3 standard deviations fro 16 inches.

(b) Is 22 inches far away from a mean of 16 inches?

3 standard deviations, more than two, so yes, 22 inches is far away from a mean of 16 inches.

(c) Suppose the standard deviation of the underlying data is 4 inches. Is 22 inches far away from a mean of 16 inches?

Now [tex]\sigma = 4[/tex]

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{22 - 16}{4}[/tex]

[tex]Z = 1.5[/tex]

1.5 standard deviations from the mean, so 22 inches is not far away from the mean.

Answered below.

Step-by-step explanation:

1) A double - blind study is simply an experiment in which neither the participants nor the people who carry out the experiment know who is receiving any particular treatment. This method is usually used in order to prevent a biased view in research results.

2) True because randomized simply means that subjects were assigned to the group randomly.

3) Placebo - controlled trial simply means that there was a control group that received only a placebo treatment which is mainly designed not to have real effect.

b. 5

Step-by-step explanation:

In a stem and leaf plot, each observation is split into a stem (the first digit or digits) and a leaf (usually the last digit).

In this example, the entries in the 20s, 30s, and 40s are:

20, 20, 24, 25, 26, 35, 36, 43, 43

We omit 20, 20, 43, and 43 because they are not between 20 and 40.

That leaves the five observations

24, 25, 26, 35, 36

If your score is the 85th percentile this means that your score is above the 85% of the total population. If your score is in the 50th percentile this means that your score is above the 50% of the population.

The qualifying standard for the Presidential award is the 85th percentile. The 85th percentile is going to be different depending on the age and gernder. Jane was able to meet the standard but Matt wasn't. This means that the score (40 curlups) is above the 85% of the total number of scores for the population of 9 year old girls, but is is below the 85% if the total number of scores in the population of 12 year old boys. This means that the performance of Jane was better.

The standar for the National award for Matt is 40, which was his own score. This means that Matt's score corresponds to the 50th percentile. Again, it is evident that the performance of Jane was better because her score was above the 85th percentile.

In the given data reported poll on a new Zealand.

The article reported that new Zealanders favors the law by a margin of 56.4% to 39.3%

These difference in results in which poll is likely to be more reliable is that the San Francisco Bay Times utilized the Voluntary Response technique ( Voluntary reaction strategy is self chosen technique, it's kin decision whether to give reaction or not). So the two surveys can give such generally varying outcomes.

Thus their survey results can't be viewed as dependable

See the attached picture for answer.

Explanation:

See the attached picture for explanation.

[tex]Artery disease. An article in the New England Journal of Medicine describes a randomized controlled[/tex]

A) The 95% confidence mean that out of 100 people, there are 95 people who voted for Ringel in the poll.

b) The newspaper would say that the results were too close to call because of the margin of error of 2% which would mean that the Ringel could have 50% to 54% and 50% is not definitive

I do not understand how to solve it

she gotta workk that a 2

step-by-step explanation:

54.864 meters

step-by-step explanation: