will some please help me with 10 questions i really need to pass this...?

Question

anonymous · Answer

A company sponsors four races a year: one in the spring, one in the summer, one in the fall, and one in the winter. The chart below shows the number of participants in each race in 2008 and 2009.

Race	Participants
in 2008	Participants
in 2009	% Change
(approx.)
Spring	2,416	2,899	+20%
Summer	1,014	963	-5%
Fall	5,785	6,942	+20%
Winter	3,422	3,559	+4%

Based on the chart, which claim misuses the data?
The number of participants in the fall race increased by about 20%.

The number of participants in the summer race decreased from 2008 to 2009.

The number of participants in the spring and fall races both increased by the same number of participants from 2008 to 2009.

The number of participants in the spring, fall, and winter races all increased by at least 3% from 2008 to 2009.

whpalmer4 · Answer

Well, let's look at the data!  

Claim #1: number of participants in the fall race increased by about 20%

Fall 5,785 6,942 +20%

Looks like that's a valid claim, no?

Claim #2: the number of participants in the summer decreased from 2008 to 2009.

Summer 1,014  963  -5%

Again, looks like a valid claim, right?

anonymous · Answer

yes but im very condused

anonymous · Answer

confused

whpalmer4 · Answer

Okay, what has you confused?

anonymous · Answer

every thing im suppose to pass this and we have not yet learned it

whpalmer4 · Answer

Are you confused about the two claims we talked about so far?

anonymous · Answer

yea can u show me how to do this problem and then see if i get it...?

whpalmer4 · Answer

Okay, here's how you do this problem: you look at each claim, and the data, and see if the claim is true.  If it is, you move on to the next claim, until you find a claim that is not true.

Are you able to read the data in the table?

anonymous · Answer

yes

whpalmer4 · Answer

Okay.  Look at what I said about the first two claims.  Do you have any questions about how I concluded that they were true?

anonymous · Answer

yes

anonymous · Answer

wait it was c...? right

whpalmer4 · Answer

Let's look at the claim for C:

The number of participants in the spring and fall races both increased by the same number of participants from 2008 to 2009.

Spring	2,416	2,899	+20%
Fall	5,785	6,942	+20%

Yes, they both increase by 20% from 2008 to 2009, but 20% of 2,416 is a different number than 20% of 5,785.

Therefore, C is not a valid claim.

anonymous · Answer

okay what about this one

anonymous · Answer

Scott took a part time job as a pollster for the Stonebridge Mall. He was assigned to stand at the west entrance of the mall and approach every 25th person coming into the mall to ask a few questions. While counting the people who passed by, he skipped everyone that he knew. Identify the one piece of information that might be a source of bias.
He stood at the west entrance of the mall.
He skipped everyone that he knew.
He only approached people coming into the mall, not those going out.
He only asked every 25th person.

whpalmer4 · Answer

What do you think?  An important point is that when sampling, you need a representative sample, one that accurately reflects the population you are sampling.  Are any of things likely to make his sample not representative?