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need help on solving stem- and- leaf- plots

ok so i need some help understanding these see the way my teacher is show how to solve them is making it very difficult to understand and i make thing so much harder so i need some to dum stem- and- leaf- plots down to where a 1st grader could understand it

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Could you give me an example of a problem so that I can better understand how to answer this question? Thanks!

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2 Answers

Basically, let's say you have a collection of data represented by a stem and leaf plot.

1 | 01123335579

2 | 2446999

4 | 22223445578

The way you read it is as follows.

In each row is a ten's digit to the left of the stem. For each digit on the right, appending it to the tens digit gives a number in the data.

For example the sample data represented in the above plot includes a 10, a pair of      11's, a 12, three 13's, etc.

 

Hi Zak,

 

I'm going to give you an example of stem-and leaf plotting.

Suppose that you have a data set that's as follows:

x={1, 2, 4, 5, 11, 15, 19, 20}

The stem (left side), is the first digit of the data. The leaf (right side) is the second digit. So plotting the above data set on a stem and leaf plot will result in the following

0   | 1, 2, 4, 5

1   | 1, 5, 9

2   | 0

The idea is that by looking at it this way you can get an idea of where most of the data lies. Here you can see that most of it is in the single digits and that as the numbers go up there are fewer of them.

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Great explanation, Zoltan. I would add that if you consider what questions you can answer, the plots will begin to make more sense. If you just wanted to know min, max, and range, you could easily get that by ordering the data. This plot should make it easier to answer tougher questions than that, and it does.

For example, let's say the above plot represents a survey of coins in your pocket. "How many people surveyed have fewer than 10 coins in their pocket?" 4  "If we were to survey a lot more people, we'd expect the typical #coins to be about what?" Between 5 and 11 coins (Note there several reasonable ways to answer this one.)

The other thing to note is that you define the stem and leaf in a way to help you answer the questions you want. For example, let's say the data set is this.

a = {120, 125, 160, 220, 280, 534, 887, 910}

Your key (stem and leaf definition) could be 1 | 20 = 120 OR 12 | 0 = 120

If you want to answer questions ("analyze") based on the hundreds place, then you would use the first one: 1 | 20 = 120. If you wanted to focus on the resolution of the last digit for each stem, you may choose the second one: 12 | 0 = 120.

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