2TH §2.5 Stem+Leafdiagram

• Wiskunde
• Middelbare school
• havo, vwo
• Leerjaar 2

Plan for today

• Entry ticket
• §2.5 Stem and Leaf diagram
• Homework: Exercises 27, 28, 29, 30, C7

Learning goal: You will learn what a stem and leaf diagram is

Entry ticket

What's the mean?

1. 1,9
2. 2,0
3. 1,8
4. 0,4

Entry ticket - solution

§2.5 Stem-and-leaf diagram

So more on 'Statistics'.

Is this everybody's cup of tea?!

First a short Refresh on §2.4 Mean, mode and median.

The MEAN follows in the next slide.

We do 26 together now:

Sophie has measured the lengths of 40 pupils.

But she's doesn't have a good overview yet.

She wants to order all these lengths in a better way.

See next slide.

Josh uses an even clearer way.

Try to understand what he he has done!

Task:  What percentage of the pupils is shorter than 

160 cm? There are 40 pupils.   ANS

.... % is shorter than 160 cm

Solution:

Another Solution:         5/40 x 100 % = 1/8 x 100 % = 12.5 %

So you can also do it without a ratio table!

In the next example Josh's method is used again.

You also get an explanation about it!

Homework  

• Do and correct the following exercises 27, 28, 29, 30, C7 

• Correct your answers with another colour
• Later this lesson there is a short addition to this Lessonup.

Short addition:

For comparing two groups of data there is a 

special stem-and-leaf diagram!

See next slide.

Double stem-and-leaf diagram

If you want to compare two groups. The stem is then placed between two vertical lines and the data for one group is place in the leaves on the left and for the other group in the leaves on the right.

When sorting the leaves,

the smallest number is written

closest to the stem.