Stat 1124: CH 3

What is a density function?

A smooth curve drawn over the histogram is a mathematical model aka ia density function
What does a smooth curve describe?(aka density curve)

It describes the overall pattern of a distribution
What shapes do density curves come in?

They come in any imaginable shape!
What are some properties of density curves?
What is Normal distributions?

Normal distrubutions are a family of symmetrical, bell shaped density curves defines by a mean (mu) and a standard deviation(sigma)
What are three characteristics of normal distrubution?
What is the Emprircal rule?

68-95-99.7
How to calculate the area under the normal curve?
What does a z-score measure?

A z-score measure the number of standard deviations that a data value x is from the mean "u".
When x is larger than the mean, z-score is ______

POSITIVE
WHen x is smaller than the mean, z-score is ________-

Negative
How to calculate z-scores (Just look)

Author

lindaphann

128374

Card Set

Stat 1124: CH 3

Description

Chapter 3: The Normal Distributions

Updated

2012-01-17T08:04:53Z