Question

please help with math

Answer 1

Quartile Ranges:

1st) 0-7
2nd) 7-Median
3rd) Median-13
4th) 13-22

Can you now evaluation the choices?

Answer 2

Obviously, that is not correct, since you selected two answers.

What does the lowest quartile mean? What percent of outcomes are LESS THAN the maximum value of the lowest QUARTILE?

Answer 3

Okay, let's back up a little. Please tell me what a Median is. What is it's definition?

Answer 4

What percent of outcomes are on each side of the median?

Answer 5

Forget the problem at hand. Just answer the question.

If you have a median, what PERCENT of outcomes are on each side?

Answer 6

Perfect. That is what we need. If we are asked ANYTHING about 50%, we are talking about the Median. If we are asked ANYTHING about the median, we are talking about 50%.

Are we given ANY information about the Median in this problem? Anything?

Answer 7

Okay, then how about we don't pick any more answers that refer to 50% or to the median. Deal?

Answer 8

Okay, now we have a Median. What's a QUARTILE?

Answer 9

Into what sort of grouping?

We established that he Median divides the data unto 50% pieces. What sort of pieces do we get when we split things up into quartiles?

Answer 10

Perfect. So, if we say the lower quartile maximum is 7, what does that mean about the data as it relates to 7?

Answer 11

No good. Try again. Think about percentages.

Answer 12

Remember that Median? Do you recall that 50% of the outcomes were on one side and 50% were on the other side? Answer with something like that.

I have the maximum of the 1st quartile. What percent of scores are below that point? What percent fo scores are above that point?

Answer 13

Let's look at it.

The lower quartile of the ages is 7.

This means the lowest quartile ranges from age 0 to age 7. This also means that 25% of the ages recorded are in this range. Or, 25% of the recorded ages are less than 7.

The interquartile range is 6.

This mean the bottom of the highest quartile is 7+6 = 13. This also means that 25% of the recorded ages are greater than 13 and you have the correct answer.

There are a couple of oddities that you need to understand. Notice how your answer choices included the very large word "approximately". I have not been saying that, just for simplicity in this discussion. It should be there. There are two things that make this APPROXIMATE, rather than exact.

1) Values ON the border (exactly 7 or exactly 13) can be a little confusing. You need to refer to your text book or course notes to make sure you know how this definition works. Is 7 in the lower quartile or in the higher quartile? Make sure you KNOW. No guessing.

2) Outliers. There may be more than 25% above 13. However, if they are also above 22, we will throw them out as outliers. As far as describing the distribution, it is 25% are above 13. As far as reality, it might be a little different.

I hope I made a little sense. You should go over this stuff a few times and make sure it soaks in.