Learning Intention


Revise the statistical measures

mean, median, mode
range, upper and lower quartiles, interquartile range

displays (graphs) which are good for showing these measures




                                  Please write this in your notes book
Find the mean of the numbers 4, 0, 3, 11 and 6.

    4 0 3 11 6          Add up and divide by the number of scores.
x
        5
    24
    5
    4 .8
Find the median of these sets of numbers:
a 4, 8, 3, 11, 6
b 3, 5, 7, 4, 9, 2
c 4, 7, 7, 3, 9, 8

a 3, 4, 6, 8, 11          First put the numbers in order.
                          Work in from the ends to find the middle.
   The median is 6

b 2, 3, 4, 5, 7, 9        First put the numbers in order.
                          Work in from the ends to find the middle.
                          The median is half way between 4 and 5.
   The median is 4.5

c 3, 4, 7, 7, 8, 9        First put the numbers in order.
                          Work in from the ends to find the middle.
                          There are two middle numbers, both of
   The median is 7        which are the same.
Find the mode of these sets of numbers:
a      6, 9, 4, 5, 7, 2, 7, 5, 7, 3
b      8, 9, 3, 8, 9, 4, 7
c      6, 12, 11, 9, 10

a 6, 9, 4, 5, 7, 2, 7, 5, 7, 3   Which number is most common?
   The mode is 7.


b 8, 9, 3, 8, 9, 4, 7            Which number is most common?
   There are two modes, 8 and 9.


c 6, 12, 11, 9, 10               Which number is most common?
   There is no mode.
Calculate the range of the numbers 10, 20, 2, 25, 11, 18, 23.

 The largest value = 25

The smallest value = 2

            Range = 25 – 2

                   = 23
Find the lower and upper quartiles for each of
   12 14 17 20 21 21 21 26

   12 14 17 20 21 21 21 26              Find the median.

The median is 20.5
Find the median of the lower group.
The low group is 12, 14, 17, 20 which has a median of 15.5

Find the median of the high group.
The high group is 21, 21, 21, 26 which has a median of 21

LQ = 15.5
UQ = 21
                  The interquartile range = 21 – 15.5
                                          = 5.5
Find the lower and upper quartiles for each of
  0 2 3 5 6 8 9 9 10 12

   0 2 3 5 6 8 9 9 10 12                Find the median.

The median is 7
Find the median of the lower group.
The low group is 0, 2, 3, 5, 6 which has a median of 3

Find the median of the high group.
The high group is 8, 9, 9, 10, 12 which has a median of 9

LQ = 3
UQ = 9                           IQR = 9 - 3
                                        =6
Find the lower and upper quartiles for each of
  45 47 52 61 77

  45 47 52 61 77                        Find the median.

The median is 52
Discard 52 so that the remaining numbers form two equal groups.
Find the median of the lower group.
The low group is 45, 47 which has a median of 46

Find the median of the high group.
The high group is 61, 77 which has a median of 69

LQ = 46
UQ = 69                           IQR = 69 - 46
                                      = 23
Think, pair, share


What display types (graphs) could you
use to display the

Median, Range, UQ, LQ and IQR ?
Geogebra




 Box Plot vs Dot Plot    per FT p.129 RHS

 Box Plot vs Histogram     per FT p.128 RHS not really covered

 Box plots (comparison)

 Mean vs median vs spread
This exercise is to be
completed on refill and
handed in for marking.
Using the Graphics Calculator to find statistics
Use the Graphics calculator to find the median, range, upper quartile, lower
quartile and inter-quartile range.

Main menu:           Stat
Delete lists:        (F6), DEL-A (F4), YES (F1)
                     (just in case there is already data there)

Enter data into list: data value, EXE (after each data value)

Calculate statistics: > (more options) (F6), CALC (F2),
                      SET (F6) (check for top option 1VAR XList: List 1)
                      1VAR (F1)

The symbols for:
Median = Med       Range = maxX—minX
lower quartile = Q1        upper quartile = Q3
inter-quartile range = Q3—Q1
Using the Graphics Calculator to graph statistics
Once you have the five point summary, use the GC to graph

Main menu:          Stat
                    The data and stats are is still there

Graph Statistics   GRPH (F1),
                   SET (F6), down arrow to Graph Type
                   Select Box (may need to > for more options) EXE
                   GPH1 will display box and whisker
L2 calc stats 08feb12

L2 calc stats 08feb12

  • 1.
    Learning Intention Revise thestatistical measures mean, median, mode range, upper and lower quartiles, interquartile range displays (graphs) which are good for showing these measures Please write this in your notes book
  • 2.
    Find the meanof the numbers 4, 0, 3, 11 and 6. 4 0 3 11 6 Add up and divide by the number of scores. x 5 24 5 4 .8
  • 3.
    Find the medianof these sets of numbers: a 4, 8, 3, 11, 6 b 3, 5, 7, 4, 9, 2 c 4, 7, 7, 3, 9, 8 a 3, 4, 6, 8, 11 First put the numbers in order. Work in from the ends to find the middle. The median is 6 b 2, 3, 4, 5, 7, 9 First put the numbers in order. Work in from the ends to find the middle. The median is half way between 4 and 5. The median is 4.5 c 3, 4, 7, 7, 8, 9 First put the numbers in order. Work in from the ends to find the middle. There are two middle numbers, both of The median is 7 which are the same.
  • 4.
    Find the modeof these sets of numbers: a 6, 9, 4, 5, 7, 2, 7, 5, 7, 3 b 8, 9, 3, 8, 9, 4, 7 c 6, 12, 11, 9, 10 a 6, 9, 4, 5, 7, 2, 7, 5, 7, 3 Which number is most common? The mode is 7. b 8, 9, 3, 8, 9, 4, 7 Which number is most common? There are two modes, 8 and 9. c 6, 12, 11, 9, 10 Which number is most common? There is no mode.
  • 5.
    Calculate the rangeof the numbers 10, 20, 2, 25, 11, 18, 23. The largest value = 25 The smallest value = 2 Range = 25 – 2 = 23
  • 6.
    Find the lowerand upper quartiles for each of 12 14 17 20 21 21 21 26 12 14 17 20 21 21 21 26 Find the median. The median is 20.5 Find the median of the lower group. The low group is 12, 14, 17, 20 which has a median of 15.5 Find the median of the high group. The high group is 21, 21, 21, 26 which has a median of 21 LQ = 15.5 UQ = 21 The interquartile range = 21 – 15.5 = 5.5
  • 7.
    Find the lowerand upper quartiles for each of 0 2 3 5 6 8 9 9 10 12 0 2 3 5 6 8 9 9 10 12 Find the median. The median is 7 Find the median of the lower group. The low group is 0, 2, 3, 5, 6 which has a median of 3 Find the median of the high group. The high group is 8, 9, 9, 10, 12 which has a median of 9 LQ = 3 UQ = 9 IQR = 9 - 3 =6
  • 8.
    Find the lowerand upper quartiles for each of 45 47 52 61 77 45 47 52 61 77 Find the median. The median is 52 Discard 52 so that the remaining numbers form two equal groups. Find the median of the lower group. The low group is 45, 47 which has a median of 46 Find the median of the high group. The high group is 61, 77 which has a median of 69 LQ = 46 UQ = 69 IQR = 69 - 46 = 23
  • 9.
    Think, pair, share Whatdisplay types (graphs) could you use to display the Median, Range, UQ, LQ and IQR ?
  • 10.
    Geogebra Box Plotvs Dot Plot per FT p.129 RHS Box Plot vs Histogram per FT p.128 RHS not really covered Box plots (comparison) Mean vs median vs spread
  • 11.
    This exercise isto be completed on refill and handed in for marking.
  • 12.
    Using the GraphicsCalculator to find statistics Use the Graphics calculator to find the median, range, upper quartile, lower quartile and inter-quartile range. Main menu: Stat Delete lists: (F6), DEL-A (F4), YES (F1) (just in case there is already data there) Enter data into list: data value, EXE (after each data value) Calculate statistics: > (more options) (F6), CALC (F2), SET (F6) (check for top option 1VAR XList: List 1) 1VAR (F1) The symbols for: Median = Med Range = maxX—minX lower quartile = Q1 upper quartile = Q3 inter-quartile range = Q3—Q1
  • 13.
    Using the GraphicsCalculator to graph statistics Once you have the five point summary, use the GC to graph Main menu: Stat The data and stats are is still there Graph Statistics GRPH (F1), SET (F6), down arrow to Graph Type Select Box (may need to > for more options) EXE GPH1 will display box and whisker