Statistics Notes ai



Download 432.92 Kb.
Page1/3
Date01.02.2018
Size432.92 Kb.
#38632
  1   2   3

Statistics Notes AII. 11


Heights:

Mean of data

Mode of data

Median of data

Paul Sturgess walks in the room. He is the tallest member of the Harlem Globetrotters at 7ft. 8 inches. How is his height going to influence the mean, median, and mode?

Mean of data

Mode of data

Median of data

If one of Mrs. Luckett’s 34 inch tall nieces comes in this class, how will her height influence the measures?

Mean of data

Mode of data

Median of data

Mean, Median, and Mode are central tendencies. Unlike these, the Standard Deviation of the data is used to describe the span of the data. Let’s look at your height data.

Data sets that have a small deviation

Data sets that have a large deviation

Standard Deviation

A statistic that tells us:

  • How far from ___________________ a certain piece of data is.




  • How _____________ _________________ the data items are in our data set.

The mathematic symbol for standard deviation is the lower case Greek letter _____________ and it looks like this:




  1. Calculating Standard Deviation

Data Set = {600, 470, 170, 430, 300}


Step 1: Calculate the ____________ .
m = _____________ mm.

Step 2: Calculate the _________________ from the mean for each element (xi) in the data set.
Step 3: ______________ each difference from Step 2.
Step 2 Step 3

600 - m = ______________ ______________

470 - m = ______________ ______________

170 - m = ______________ ______________

430 - m = ______________ ______________

300 - m = ______________ ______________



Step 4: Find the mean m (average) of the numbers in Step 3.

We call this number the ________________ and is represented by the math symbol σ2



Step 5: The standard deviation is the ________________ ______________ of the variance. s = _________________

Normal Distribution- Has data that vary randomly from the mean. The graph of a normal distribution is called the Normal Curve.

  • The mean, median, and mode are equal

  • The normal curve is bell shaped and symmetric about the mean

  • The total area under the curve is equal to one

  • The normal curve approaches but never touches the x-axis as it extends from the mean

  • Contains inflection points at µ - σ and µ + σ, where the curve changes from curving upward to downward. (µ is the mean)(σ is the standard deviation)

The mean gives the location of the line of symmetry and the standard deviation describes how much the data are spread out.



A standard normal distribution has a mean of 0 and a standard deviation of 1. It also has an area under the curve of 1.

Download 432.92 Kb.

Share with your friends:
  1   2   3




The database is protected by copyright ©ininet.org 2024
send message

    Main page