3Tvwo §8.4(A) and §10.4(B)

• Wiskunde
• Middelbare school
• vwo
• Leerjaar 3

Welcome to the 3rd long distance math lesson!

Programme for today / Homework for Thursday:

Math A:  §8.4 Box plot        or

Math B:  §10.4 Median.

Math A §8.4 Box plot, first.

Math B pupils,

please stay on the LessonUp;

+ it might be interesting to see what Math it is your classmates

are going to do

+ in a few minutes we move over to Ch 10!

Choose the correct statements in the next slide.

Remember the letter(s) of your choice!

A. The 2 numbers of an interval notation tell you the class width.

B. Relative numbers are the actual ones; absolute numbers are percentages.

C. Percentages compare to a base year are called INDEX NUMBERS.

D. The upper quartile is between 25 % of the numbers and 75 % of 

     the numbers, from left to right.

1. class width
2. relative and absolute
3. index numbers
4. upper quartile

• 
  
• Watch this picture.
• It is an illustration of what you already learnt!
• Everything plotted in a BOX, so it is a   BOX PLOT!

Do you remember from §8.3 the MEASURES of SPREAD (spreiding)?

 Here is a Summary:

• The median is the number in the middle.
• Q1 = lower quartile   is the middle number of the first half
• Q3 = upper quartile  is the middle number of the second half.
• IQR = interquartile range  is   Q3 - Q1, so the length of the Box (new!)
• range = max - min 

The next slide ...

shows you precisely how to

• calculate : median, Q1 and Q3
• draw the BOX PLOT

Math A pupils: I wish you every succes,

doing §8.4.

Now it's high time for Mat B: §10.4 !

Math B:  §10.4 MEDIAN

Do you remember and understand the previous paragraphs?

A few questions follow!

You may consult book 3B, because you do not have to know all content by heart now.

Which statement(s) is(are) correct?

They all concern triangles.

A. Perpendicular Bisectors(PB), Altitudes(A) and 

     Angle Bisectors(AB) all go through one point.

B. Making PB-s and A-s is called 'constructing', for AB-s it's just 'drawing'.

C. Making PB-s and AB-s is 'constructing', A-s you draw.

D. The vital difference between drawing and constructing is that for the

     latter you also need a pair of compasses.

Fill in the good statement(s).

1. PB-s A-s and AB-s go through one point.
2. PB-s and A-s: constructing
3. PB-s and AB-s is constructing A-s is drawing
4. difference is pair of compasses

Constructing - drawing.

When making Perpendicular Bisectors and

Angle Bisectors:              

always use a pair of compasses!

Reason: very precise results!

Exercise 18a and 18b should've asked you

to 'construct' and not just 'plot' and 'draw'.

So sad, so very sad...

By the way,

your classmates also work on the Median, but then 

it is about Numbers!

Both mean 'something in the middle'!

Drawing the median can be done with geo and pencil only.

And what bout the 3 medians of a triangle?

After dealing with §10.1, §10.2 and §10.3 you might have

expected:

all 3 go through the same point!

This is a great paragraph:

It contains, among others, these tasks: 

+ plotting or drawing                        

+ explaining

+ calculating  

+ reasoning,     examples on next slides!

plotting or drawing:

explaining:

calculating:

Perform all these different tasks 

as good as you can!

Remark:

PROVING something  is a skill that will be asked from

you in the higher forms more often!

It distinguishes (sets apart) Math B from Math A!

proving:

Homework time.