Search
Create
Log in
Sign up
Log in
Sign up
AP Statistics: Chapter 2
STUDY
Flashcards
Learn
Write
Spell
Test
PLAY
Match
Gravity
Terms in this set (35)
Density Curve
A curve that is always above the horizontal axis and has an area underneath of exactly one
Median of density curve
The "equal areas" part, the part with half the curve to it's left and right
Quartiles
Area under the curve is divided into quarters
Mean of density curve
The "balance" part
When does the mean equal the median?
When the distribution is symmetric
μ
Mean of a population
x̅
Mean of a sample
σ
Standard deviation of a population
s
Standard deviation of a sample
Normal distribution
The same general shape of symetric, unimodal, bell shaped
σ controls what?
The spread
As standard deviation increases...
The curve becomes more spread out and elongated
Empirical Rule Graph
68-95-99.7
What % of observations fall within 1σ of the μ
68%
What % of observations fall within 2σ of the μ
95%
What % of observations fall within 3σ of the μ
99.7%
With every question...
Write a given including, normal, σ, and μ
If the question says "What percent," you must draw a...
Bell curve
Percentile
Shade below
Standard value
z-score
z-score formula
z-score written formula
(sample value - population mean) / population standard deviation
z-score written formula
(statistic - parameter) / standard deviation
z-score
Tells how many standard deviations an observation falls away from the mean and in which direction it lies
z > 0
x > μ (above the mean)
z < 0
x < μ (below the mean)
Standard notation
N( μ,σ )
How many decimal places is a z-score?
Two decimal places
When the z-score isn't in Table A
1) Stat-list editor
2) F5 Distribution
3) #1 Shade
4) #1 Shade Normal
Best way to determine area
Shade normal in calculator
Okay way to determine area
Table A
Worst way to determine area
Empirical rule
Since the area under the curve at any given # is 0
< equals ≤
Since the area under the curve at any given # is 0
> equals ≥
The area under the curve at any given # is...
0
;