1. 4/19/13 Have out: Bellwork: total:
pencil, red pen, highlighter, GP notebook, textbook, graphing calculator
4/19/13
Have out:
Bellwork:
Determine the following:
end 1) 2) 3)
start
= 4(1) + 4(2) + 4(3) + 4(4) + 4(5) +1 =
= 60 +2
total:

2. Bellwork: total: Determine the following: 2) 3) +1 +1
= (1)3 + (2)3 + (3)3 + (4)3
= (3 + 2) + (4 + 2) + (5 + 2) + (6 + 2) = =
= 100
= 26 +2 +2
total:

3. Introduction to Standard Deviation
Range measures the spread of a set of data from low to high.
For example, yesterday we discussed the range of heights of an 8th grade class from 60 to 71 inches. The spread is from 60 to 71.
There are two other measures of spread. Today, we will focus on the first measure: ____________ ____________.
standard
deviation
Standard Deviation measures the spread of the data from the
mean. The larger the standard deviation, the more spread out the data is from the mean.
Example #1: Suppose you are given the following data set:
4, 6, 9, 6, 5.
Sketch a histogram of the data.

4. Introduction to Histograms
Example #1: The heights (in inches) of 20 8th graders are as follows:
63, 65, 69, 61, 62, 63, 65, 67, 69, 64, 65, 66, 66, 67, 64, 69, 68, 62, 60, 71
Rewrite the list in ascending order (or use sort on calculator).
60, 61, 62, 62, 63, 63, 64, 64, 65, 65, 65, 66, 66, 67, 67, 68, 69, 69, 69, 71
STAT
1: Edit
2nd
LIST 
OPS
2: SortA( L1 )
Enter data in L1.
ENTER
STAT
1: Edit

5. Range = _____ – _____ = _____ 71 60 11 Max Min
60, 61, 62, 62, 63, 63, 64, 64, 65, 65, 65, 66, 66, 67, 67, 68, 69, 69, 69, 71
The ______ of the data is the difference between the highest and lowest data.
range
Range = _____ – _____ = _____ 71 60 11
Max
Min
Since all measurements are to the nearest inch, there are _____ + _____ = _____ possible data points. 11 1 12
histogram
We are going to make a _________ (bar graph) where we are going to group the data into intervals.
To keep each interval the same length, use 4 intervals because 4 is a factor of ____. 12
class size 12 3
Each __________ will be ____ = ___ 4
frequency table
Make a ______________ to organize the data.

6. Class Interval Frequency
60, 61, 62, 62, 63, 63, 64, 64, 65, 65, 65, 66, 66, 67, 67, 68, 69, 69, 69, 71
Class Interval
Frequency
60 – ____
____ – ____
____ – 71
Make each interval 3#s wide  62
Make a tally of the heights within each interval 63 65 66 68 69
Mean = ______
65.3
Use your calculator to compute the following:
Median = ______ 65
Use the frequency table to make a histogram on graph paper.
Height (inches)
Frequency
Make sure that the bars touch!

7. Class Interval Frequency
Height (inches)
Frequency
60 – 62
63 – 65
66 – 68
69 – 71 2 4 6 8
Class Interval
Frequency
60 – ____
____ – ____
____ – 71 62 63 65 66 68 69
Make sure to include a “break.”

8. Let’s make the same histogram on a graphing calculator
Let’s make the same histogram on a graphing calculator. First, however, clear all functions of the menu.
Y =
2nd
STAT PLOT
1: Plot 1
ENTER ON
TYPE
Make sure all other plots are turned off.
Choose histogram
Arrow over, highlight, and hit
ENTER

9. Once you select histogram, make sure the screen shows:
X list: L1
Freq: 1
Select
ZOOM
9: ZoomStat
ENTER
Arrow down 6
This makes ____ intervals, but we just want 4 intervals. Therefore, we need to change the window.

10. Select WINDOW 60 72 3 –1 8 1 Select Select GRAPH TRACE
Xmin = ___ Xmax = ___ Xscl = ___ Ymin = ___ Ymax = ___ Yscl = ___
MIN
MAX + 1
Class size
Most at any interval + 1
Select
Select
GRAPH
TRACE
Notice the intervals and frequency

11. Example #2: A police officer clocked the following speeds (in mph) in a Wal-Mart parking lot.45 52 46 42 40 51 47 36 34 59 32 56 38 29 15 49 35 41 39 64 24 55 10 25 48 21
Record the data into L1 and sort ascending (see your notes from day 1). Be sure to clear the previous data from L1.
To avoid data entry mistakes, make sure that the mean of the above data is about
2nd
QUIT
2nd
LIST 
MATH
3: mean( L1 )

12. To make one, complete the following steps: 1. Draw a vertical line
A ______ - ____ - _____ Plot is a way to organize and analyze statistical data.
stem
and
leaf
To make one, complete the following steps:
1. Draw a vertical line
2. On the left side of the line, list all the numbers that are in the 10s place from the set of data.
3. List each number in the ones place on the right side of the line in ascending order.
Stem
Leaves 1 5 2 1 4 5 9 3 2 2 4 5 5 6 6 8 9 4 1 1 2 5 5 6 7 8 9 5 1 2 2 5 6 9 6 4
By the way, if you turn the stem–and–leaf plot 90 degrees, it looks like a histogram.

13. Since there are 32 data points, the median is equal to the average between the ____ and ____ points when data is in ascending order.
16th
17th
Stem
Leaves 1 5 2 4 9 3 6 8 7
Median = 40
+ 41 2
= 40.5
On graph paper, make a histogram for the car speed data with 5 intervals of equal length.
speed (mph)
Frequency

14. But first, let’s answer the following:
Range = ____ – ____ = ____ 64 10 54
Max
Min 54
Class size =
= ____ 55
= ____ 11 5
Make a frequency table to organize the data.
Stem
Leaves 1 5 2 4 9 3 6 8 7
Class Interval
Frequency
10 – ____
____ – ____
____ – 64 20 21 31 32 42 43 53 54

15. Class Interval Frequency
10 – ____
____ – ____
____ – 64 20 21 31 32 42 43 53 54
speed (mph)
Frequency
10 – 20
21 – 31
32 – 42
43 – 53 4 8 12 16 2 6 10 14
54 – 64

16. Assignment #2
DS 29, 30, 50, 53 – 57
c) CST Packet #49 – 56