Counting Strat.
what counting method is used when order matters?
nPr
what does a z-score measure?
how many standard deviations a value is from the mean
what shape is a normal distribution?
bell shaped
what is the average of a data set called?
mean
what is the mean of 2,4,6,8,10?
6
what counting method is used when order does not matter?
nCr
what z score represents the mean
0
what percentage of data falls within 1 standard deviation of the mean?
about 68%
what is the middle value in a data set?
median
what is the median of 1,3,5,7,9?
5
how many ways can 3 students be chosen from 5 students?
10
is a z score of -2 above or below the mean?
below the mean
what percentage of data falls within 2 standard deviations?
about 95%
what is the most frequently occurring value?
mode
a z score of 0 means the value is where?
at the mean
how many outcomes are possible when flipping a coin twice?
4
what is the formula for a z score
z=(x-m)/o
what percentage of data falls within 3 standard deviations?
about 99.7%
which measure shows how spread out data is?
standard deviation
does a combination consider order?
no
what principle multiples the number of choices for each step?
fundamental counting principles
which z score is farther from the mean: 1.5 or -2.5?
-2.5
what rule describes the 68%, 95%, and 99.7% percentages
the empirical rule
what is the difference between the highest and lowest values?
range
in a normal distribution, approximately what percent of data falls within 2 standard deviations of the mean?
95%