501_Lecture_01-3 - Section 1.3 The Normal Distributions...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
Section 1.3 The Normal Distributions
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Topics Density curves Normal distributions The 68-95-99.7 rule The standard normal distribution Normal distribution calculations Standardizing observations Normal quantile plots
Background image of page 2
Density curves
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Density curve Imagine a smooth curve thru the top of the bars on a histogram: it is an idealized mathematical model for the data Curve lies on or above the horizontal axis (non-negative) Has area exactly = 1 underneath it. Area under this curve for a given range give an estimate of the chance of an observation falling in that range Let’s look again…
Background image of page 4
Density curves
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Definitions Mode Location where the curve is high-peaked Median the equal-areas point. Half the area on each side. Mean the balance point of the density curve Think of placing a wedge so that the density would balance like on a see-saw or teeter totter Hard to visually find the mean for skewed curves Mathematical formulas are used to calculate the mean, median, standard deviation, etc.
Background image of page 6
Normal Density Curve
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
A right skewed density curve
Background image of page 8
Mean is the balance of the density curve
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Symbols μ mean of the idealized distribution (of the density curve) σ standard deviation of the idealized
Background image of page 10
Image of page 11
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/20/2012 for the course STAT 501 taught by Professor Staff during the Spring '08 term at Purdue University-West Lafayette.

Page1 / 33

501_Lecture_01-3 - Section 1.3 The Normal Distributions...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online