Download The next example - De Anza College

The following data
shows the number
of movies 88
students watched
one week during
the summer.
Number of
movies
0
Frequency
25
1
18
2
24
3
16
4
5
TOTAL: 88
• First, enter the data into your calculator. STAT, EDIT, put # of
movies in L1 and Frequency in L2.
• Second, calculate the following by going to STAT, CALC,1-Var
Stats, type L1,L2,Enter
The sample mean is 1.52.
The sample standard deviation is 1.24.
The first quartile is 0.
The median is 2.
The third quartile is 2.
The IQR is 2.
Enter the data into your calculator. Graph a histogram.
Step 1. Access graphing mode. [STAT PLOT]
Step 2. Select <1:plot 1> To access plotting - first graph.
Step 3. Use the arrows navigate go to <ON> to turn on Plot 1. <ON> ,
Step 4. Use the arrows to go to the histogram picture and select the histogram.
Step 5. Use the arrows to navigate to <Xlist>
Step 6. If "L1" is not selected, select it. [L1] ,
Step 7. Use the arrows to navigate to <Freq>.
Step 8. Assign the frequencies to [L2]. [L2] ,
Step 9. Go back to access other graphs. [STAT PLOT]
Step 10. Use the arrows to turn off the remaining plots.
Step 11. Access [WINDOW]
Step 12. Xmin = -0.5
Xmax = 4.5
Xscl = 1 (width of bars)
Ymin = 0
Ymax = 30
Yscl = 5 (spacing of tick marks on y-axis)
Xres = 1
Step 13. Access [GRAPH]
Enter the data into your calculator. Graph a boxplot.
Step 1. Access graphing mode.[STAT PLOT]
Step 2. Select <1:Plot 1> to access the first graph.
Step 3. Use the arrows to select <ON> and turn on Plot 1.
Step 4. Use the arrows to select the box plot picture and enable it.
Step 5. Use the arrows to navigate to <Xlist>
Step 6. If "L1" is not selected, select it.[L1] ,
Step 7. Use the arrows to navigate to <Freq>.
Step 8. Indicate that the frequencies are in [L2]
Step 9. View the box plot.[GRAPH]
The following data
shows the lengths
(in minutes) of 64
international
telephone calls
using a prepaid
calling card.
Length of Call Frequency
4
25
14
15
24
10
34
9
44
4
54
1
• First, enter the data into your calculator. STAT, EDIT,
put # of movies in L1 and Frequency in L2.
• Second, calculate the following by going to STAT,
CALC,1-Var Stats, type L1,L2,Enter
The sample mean is 16.97
The sample standard deviation is 13.65.
The first quartile is 4.
The median is 14.
The third quartile is 24.
The IQR is 20.
Plot
•Boxplot – follow the same instructions as before
•Histogram – follow the same instructions as before but
change xmin to 3.5, xmax to 54.5, xscl to 10, ymin to 0 and
ymax to 30
Does the histogram of the movie
data appear to be
•Skewed right? This is the right answer.
•Skewed left?
•Symmetrical?
Are their any potential outliers for the
movie data (values that do not seem to
“fit” the rest of the data)?
•Are there any values 1.5*IQR above Q3?
•Are there any values 1.5*IQR below Q1?
Potential Outliers require further
investigation.
1.5*IQR = 1.5*(Q3-Q1) = 1.5*(24-4) = 30
•Are there any values 1.5*IQR above Q3?
Q3 + 1.5*IQR = 24 + 30 = 54
NO. The largest value is 54.
•Are there any values 1.5*IQR below Q1?
Q1 – 1.5*IQR = 4 – 30 = - 26
NO. The smallest value is 4.