A girl scout troop sold cookies to raise funds. Each troop member recorded the number of boxes she sold. The number of boxes sold was normally distributed with a mean of 22 boxes sold and a standard deviation of 4 boxes. In order to help determine how many boxes would be sold the next year, the troop leader decided to focus on the range made from the bottom 30% to the top 20%. Find the number of boxes that represent the desired range values.

22 and 26
20 and 25
22 and 24
21 and 24

I think it's C but I have no real idea how to do this so if someone could explain I'd appreciate it.

its 20-25

So, if you have no idea, why do you think it's C?

You can play around with Z table stuff at

http://davidmlane.com/hyperstat/z_table.html

Because I'm supposed to make a guess so I made one...

But I really don't know how to do it, or what a z table is but ok.

To find the number of boxes that represent the desired range values, we can use the concept of z-scores. The z-score measures the number of standard deviations an individual data point is from the mean.

First, we need to find the z-scores corresponding to the cutoff points for the desired range.

For the bottom 30%, we need to find the z-score that represents the value below which 30% of the data lies. We can use a standard normal distribution table or calculator to find the z-score corresponding to 30%. In this case, it is approximately -0.524 (rounded to three decimal places).

For the top 20%, we need to find the z-score that represents the value above which 20% of the data lies. Again, we can use a standard normal distribution table or calculator to find the z-score corresponding to 20%. In this case, it is approximately 0.841 (rounded to three decimal places).

To calculate the actual values in terms of the number of boxes, we use the formula:
x = z * σ + μ
where x is the desired value, z is the z-score, σ is the standard deviation, and μ is the mean.

Using the given information, the mean is 22 boxes and the standard deviation is 4 boxes.

Start with the bottom 30%:
x1 = -0.524 * 4 + 22 = 20.704
Since we are dealing with whole numbers of boxes, we can round it down to 20 boxes.

Now, move on to the top 20%:
x2 = 0.841 * 4 + 22 = 25.364
We can round this up to 26 boxes.

Therefore, the desired range values are between 20 and 26 boxes, which corresponds to option A: 22 and 26.