Laura's Responses in WyzAnt Answers

A simpler explanation would be all angles inside a square are equal to 90°.  If you have a shape that has 4 equal sides, but only opposite angles are equal, it's a diamond.  A diamond is a type of parallelogram.

First off, we need the equations to really help you with this.  I can only give you a generic answer without them.

I can tell you that for (a) to be correct, you will get an ordered pair (i.e. one value for x and one value for y). For (b) to be correct, you will get some useless-but-true answer (i.e. 8=8).  Usually this means that both equations are different forms of the same line.  For (c) to be correct, you will get an untrue answer, such as 0=-4.

Hi Mildred,

It sounds like what you are doing in this question is a two-tailed hypothesis test.  Also, from what you've given, it seems like you don't have the standard deviation for the whole university (population SD).  Therefore, you would normally want a two-tailed t-test, however, since the sample size is so large, you can probably assume a normal distribution and use a Z-test.

First, you want to come up with your null and alternative hypotheses:  H₀: μ = 3.1 (true mean is 3.1, so sample and population are not different); H_A: μ ≠ 3.1 (true mean is not 3.1, so sample and population are different)

To calculate the Z-statistic, use:  Z = (X - μ)/(σ/√n)

Where μ = population mean (whole university), X = sample mean, σ = SD and n = number in sample.  You have the formula right in your question.

Now, since you are using a 92% CI, but really you have a two-tailed situation, each tail will have 4%. You want to find that 4% on a Z chart (added to 92%).  I found that ~.96 occurs at Z ≤ 1.75.  So, if you want to reject H₀, your Z value must be smaller than -1.75 or larger than 1.75.  Remember, H₀ is that your sample mean and population mean are the same (i.e. NOT significantly different).

I would think of this problem as a big right triangle.  Draw a triangle like this on your paper:  /|

The slanted line should be labeled 10,300 feet at the bottom and 12,300 feet at the top.  Think of this slanted line as how the skiers went down the mountain.

The line that's straight up and down is the height of the mountain (i.e. the "imaginary line that extends from the top of the mountain to it's base").  You don't know how high that is yet.

The line across the bottom (horizontal) is the 3,000 feet.

Now, what is the actual question?  Do you need to find the slope of the part of the mountain the skiers skied on?

slope = rise / run OR slope = how far did you move vertically / how far did you move horizontally

Well, the skiers moved down the mountain from 12,300 to 10,300 feet.  Subtract those and you get how far they moved vertically (i.e. the "rise").  This is also the height of your triangle (the part you didn't know yet from above). Remember, moving down is negative and moving up is positive.

Now, the horizontal movement is the distance from the skiers at the bottom of our triangle to the imaginary line coming down from the peak to the base.  That information is given to you directly in the problem and that is your "run".

Should that be + 5a at the end? or are you missing some +s and -s between the 14 and 3 and between the xyz and 5?

Step 1:  Use the distributive property on (30x -7)yz

Step 2:  Combine like terms (eg. all constants, all ___xyz's)