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#### BalooTheBear

QR125: The ratios are equal between men and woman. Then the number of men decreases by 20% and the number of woman increases by 20%. What is the current ratio of men to woman?

I got 2/3 for this but it says the correct answer is 3/2. Do I have the ratio concept backwards or is this an error?

QR140: What is the equation of the line of symmetry of the equation:

x^2 = 4(y+2) - 16

The correct answer is x=0

Do we need to know parabola stuff, because I don't really know it that well.

QR152: The temperature for the first week of the month of January were recorded as follows: 5, 10, 15, 8, 13, 17, 9. What is the mean and standard deviation of the set of data?

Correct answer is 11 and 3.9.

My question is how and I supposed to determine standard deviation? I understand how to get mean, but am so lost with standard deviation.

I also have another question from my Kaplan Blue Book CD-Rom practice test:

If one car travels 24mph in one direction and then turns around and goes back to its original location at a speed of 48mph, what is the cars average speed?

The CD-rom did not give me the correct answer.

Thank you for your help. I'm going bald from stress. Only 3 weeks and 1 day till the real thing!!!