Probability and Statistics
posted by Amber on .
For question 1, here's the numbers you use: {20, 18, 17, 19, 22, 29, 16, 27, 24}.
1. Calculate the 50th percentile.
For questions 2 and 3 use this number line: {16, 17, 18, 19, 20, 22, 24, 27, 29, 80}
2. Calculate the zscore for the 80 & explain what it means. (Explain what the zscore is.)
3. Calculate the zscore for the median of the data set.
I've tried doing these problems with no help from my teacher. Please help?
Thanks

Here are a few hints:
1. The 50th percentile is the median. Put the numbers in order and determine the middle number. If you have an odd data set, the middle number is the median. If you have an even data set, take the middle two numbers, add them, then divide by 2 for the median.
2. Find mean and standard deviation. Then use zscores. Formula for zscores is: z = (x  mean)/sd
(Note: x = 80)
3. Determine the median. Use the formula above to calculate the zscore for the median.
I hope this will help get you started.