# 2.5 Stem and leaf displays

Introduction to stem and leaf plots.

A stem and leaf display is a graphical method of displaying data. It is particularly useful when your data arenot too numerous. In this section, we will explain how to construct and interpret this kind of graph.

As usual, an example will get us started. Consider . It shows the number of touchdown (TD) passes

Touchdown Pass: In American football, a touchdown pass occurs when a completed passresults in a touchdown. The pass may be to a player in the end zone or to a player who subsequently runs into the end zone. Atouchdown is worth 6 points and allows for a chance at one (and by some rules two) additional point(s).
thrown by each of the 31 teams in the National Football League in the 2000season.

A stem and leaf display of the data is shown in the below. The left portion of the table contains the stems. They are the numbers3, 2, 1, and 0, arranged as a column to the left of the bars. Think of these numbers as 10's digits. A stem of 3 (forexample) can be used to represent the 10's digit in any of the numbers from 30 to 39. The numbers to the right of the bar areleaves, and they represent the 1's digits. Every leaf in the graph therefore stands for the result of adding the leaf to 10times its stem.

 3|2337 2|001112223889 1|2244456888899 0|69

To make this clear, let us examine this more closely. In the top row, the four leaves to the right of stem 3 are 2, 3, 3, and 7. Combinedwith the stem, these leaves represent the numbers 32, 33, 33, and 37, which are the numbers of TD passes for the first fourteams in the table. The next row has a stem of 2 and 12 leaves. Together, they represent 12 data points, namely, two occurrencesof 20 TD passes, three occurrences of 21 TD passes, three occurrences of 22 TD passes, one occurrence of 23 TD passes, twooccurrences of 28 TD passes, and one occurrence of 29 TD passes. We leave it to you to figure out what the third row represents.The fourth row has a stem of 0 and two leaves. It stands for the last two entries, namely 9 TD passes and 6 TD passes. (Thelatter two numbers may be thought of as 09 and 06.).

One purpose of a stem and leaf display is to clarify the shape of the distribution. You can see many facts about TD passesmore easily in than in the . For example, by looking at the stems and the shape of the plot, youcan tell that most of the teams had between 10 and 29 passing TDs, with a few having more and a few having less. The precisenumbers of TD passes can be determined by examining the leaves.

We can make our figure even more revealing by splitting each stem into two parts. The below shows how to do this. The top row is reserved for numbers from 35 to 39 and holds only the 37TD passes made by the first team in the . The second row is reserved for the numbers from 30 to 34 and holds the 32, 33, and 33 TD passesmade by the next three teams in the table. You can see for yourself what the other rows represent.

#### Questions & Answers

where we get a research paper on Nano chemistry....?
what are the products of Nano chemistry?
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
Preparation and Applications of Nanomaterial for Drug Delivery
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
I only see partial conversation and what's the question here!
what about nanotechnology for water purification
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
how did you get the value of 2000N.What calculations are needed to arrive at it
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