Chebychev's Rule
True or False: Chebychev theorem is based on a symmetrical and bellshaped curve.
False: It's unsymmetrical
If nothing is said about about shape we use Chebychev.
True or False: when finding the percentile the data does not have to be in order.
False
What two percentages do we use for this theorem?
75% and 88.9% (89%)
What are the Quartiles called and what percent does each one stand for?
Q1 25%
Q2 50%
Q3 75%
What does K mean?
K is the standard deviation that lies between either 75% or 88.9%
What is the equation to find a percentile?
P/100 x N
The mean score on an accounting test is 80, with a standard deviation of 10. Between which two scores must this mean lie to represent 8/9 of the data set?
The mean score of 60 with a standard deviation of 10 must lie between 50 and 110 to represent 88.89% of the data set.
Tell me how to find 25th percentile in the calculator :
12, 3, 27, 15, 8, 19
1) Stat -> Edit
2) Plug in the list of numbers (it can be out of order in the calculator)
3) Stat -> Calc *make sure list if L1
4) Calculate then scroll to Q1
Mean= 80
Standard Deviation= 5
What percent are between 70 and 90?
What percent are between 65 and 95?
75% and 88.9%
How to find 85th percentile of this data (worked out).
95, 88, 70, 75, 83, 70, 66, 91, 68, 76, 82
1) order 66, 68, 70, 70, 75, 76, 82, 83, 88, 91, 95
2) 85 / 100 x 11 (number of positions)
3) 9.35 = 10
5) the 10th number in the data set is 91 so 91 is the start of the 85th percentile