__a comment to this post__, please discuss each of the graphs below. Be sure to address the questions under each graph. Please don't copy the questions or number your answers, rather, you should write a paragraph or two in complete sentences so your reader knows what you are talking about. Be sure to sign in as "anonymous" but put your first name and last initial in the post so I know to whom to give the credit. If you have any questions please e-mail me. Review the "how to e-mail a teacher" post on my blog before you send your e-mail.(click on the graphs to enlarge)

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What can we see from the above scatter plot of hair length vs. height? Is there a correlation? How strong is it? If so, is it positive or negative; strong or weak?

Graph 2

Height vs. Shoe Size

Height vs. Shoe Size

Height Vs. Shoe Size Correlation Coefficient r = 0.72 |

Above is the data we collected about our shoe sizes vs our heights. Can you see a relationship? Is there a correlation? If so, is it positive or negative? How strong is it? Does shoe size cause height to change? Does height cause shoe size to change? What about the person who is over 160 cm tall, but has the smallest feet in class? They're the about same height as two of the people with the largest feet in class.

Graph 3

Shoe Size vs. Hair Length

Shoe Size vs. Hair Length Correlation Coefficient r = -0.42 |

Finally, the above graph shows the relationship between shoe size and hair length. Is there a correlation? If so, is it positive or negative? How strong is it? The points are clustered in an interesting way (one cluster below 20cm hair length and one cluster above 48 cm hair length.) What third variable which is not shown on any of the graphs might be causing the relationship between shoe size and hair length? Does correlation imply causation? Why or why not? How about that high value for Shoe Size?

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## 9 comments:

F. L

Hair Length Vs. Height don't have any relationship between both of these variables. As shown on the graph people that are taller have short hair length and people that aren't taller have long hair. it doesn't depend if you tall or small the hair length doesn't remain the same it changes. There is no correlation between variables. It's negative and weak. This graph shows us that our class don't have any relationship between these variables. Yes there is outliers in this graph and a better was to interpret this graph should be using a line graph.

Yes there is a relationship between shoes size vs. our heights and there's a correlation between these variables. Height cause shoe size to change. Probably the person that is tall and has small feet could be that the person is different from others.

Yes in the above graph there's a correlation relationship. The third could be gender because boys have short hair length and girls have long hair length and their shoe size are different. No correlation doesn't cause causation because there is a cause and effect between relationship of two variables.

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phil c.

From the chart length vs. height, we can see that there is a strong, negative correlation. This information tells us that the taller the students are, the shorter the hair is. There are a few unusual points like the one that is taller than 170 cm and has hair length close to 50 cm. If we were to throw these points out, the correlation would be stronger. The gender being included would be helpful to better interpret the data.

In the chart height vs. shoe size we can see that the bigger the shoe size, the taller the person is or the other way around. There is a strong, positive correlation. Correlation does not imply causation. There might be a relationship between the two variables, but it may not mean they cause each other.

In the chart shoe size vs. hair length, there is a weaker, negative correlation. The third variable that might be causing the relationship between shoe size and hair lengthmay be hair length preference. Correlation does not imply causation because shoe size and hair length may not cause each other and there could be other variables affecting the data.

-Sandra F.

From the chart length vs. height, I can see that there is a strong, negative correlation. The information shows us that the taller the students are the ones with shorter hair. And the shorter students have longer hair. One unusual point is the student that is taller than 175 cm and has their hair length close to 50 cm. If we were to throw these points out, the correlation would be stronger. Also if we would get the gender being it would be helpful to give us a better understanding of the data.

In the chart height vs. shoe size I can see that the person with the bigger shoe size tends to be the taller the person same the other way around. There is a strong and it is positive correlation. Most cases height may have an effect on shoe size but not all the time.

In the chart shoe size vs. hair length, there is a weak, negative correlation. The third variable that might be causing the cluster of points is the gender of the people. Correlation does not imply causation because shoe size and hair length may not cause each other effect. There could be other variables affecting the data.

-Angel F

Graph 1:

From the scatter plot of hair length vs. height, we can see that the taller the person is the shorter the hair and the shorter they are the longer their hair, for a few exceptions who are tall with long hair or short with short hair. There is a strong correlation in this graph, it is also negative since the line goes down. This graph shows there are more people with longer hair and short then their are tall people with short hair.

Graph 2:

From the shoe and height graph, you can see how some shorter people have relatively smaller shoe sizes and taller people have bigger sized shoes. There is a strong, positive correlation going on here. In some cases height might change the size of someone's feet, but not always, some people have bigger shoe size but are short or are taller and have smaller shoe sizes. Shoe size can’t always tell everyone's height, the same being for a person's height can’t always determine their shoe size.

Graph 3:

For the shoe size and hair length, there is a weak, negative correlation happening. A third variable could be gender, but not always. Most of the boys have shorter hair lengths while most of the girls have more longer lengths. Causation is not caused by correlation, hair length and shoe size have no connections to one another for one to cause the other to change.

~ Angelica G.

From the graph of hair vs. height we can see that there is a moderate not too strong negative correlation between the variables. This graph tells me that the taller the students are, the shorter the hair may be, but it is not true in every case. Yes there are a few data points that seem a bit odd, for example, some short people also had short hair. If we were to throw these odd points out of the correlation graph then the correlation would be stronger. To interpret the data it would be helpful to have other variables like, gender.

In the height vs.shoe size data I can see that the taller the person the bigger the shoe size and the bigger the shoe size then the taller the person. There is a positive strong correlation since the correlation is 0.72 which is close to 1. We can’t say that shoe size cause height to change or that height causes shoe size to change since there was a student with feet the length of the taller people, but that person was shorter. While in graph three we can see that there is a weak negative correlation between shoe size and hair length. The third variable that may be causing the relationship between hair length and shoe size may be hair length preference. Correlation does not imply causation because shoe size does not cause your hair to be longer and longer hair does not cause your feet to grow. The bigger shoe sizes with short hair may be caused by the third variable not necessarily the person’s height caused their hair to become short and vice versa.

Elizabeth G.

Graph 1

Looking at the scatter plot of hair length vs. height, there seems to be a correlation. The correlation is negative and it is strong. The information that the graph gives about the students is that students who are taller tend to have shorter hair and people who are shorter tend to have longer hair. There doesn't seem to be any outliers as the data does seem pretty accurate. If there are a few outliers, throwing them out of the data can cause the correlation to still be negative, but it'll be weaker.

Graph 2

Looking at the scatter plot of height vs. shoe size, there seems to be a correlation as well. The correlation seems to be positive and strong. Shoe size does not cause the height to change. Height does cause shoe size to change. The person who is 160 cm tall and has small feet may have small feet because of their genes.

Graph 3

There does seem to be a correlation on this scattered plot of shoe size vs. hair length. The correlation is negative, but it's weak. The student’s personal preference can be a third variable that is not shown on any of the graphs. Correlation does not imply causation. Correlation doesn't imply causation because not all variables simplify an actual relationship between each other.

-Diego P.

There is a weak negative correlation in graph 1. Taller people might have shorter hair while shorter people (most likely girls) might have longer hair. There are a few outliers, like the person who is 145 cm tall with 15cm hair, but the correlation is still there.

On the contrary, graph 2 has a very strong positive correlation between height and shoe size. Although this graph has a few outliers, you can see that a taller person might need larger feet.

Lastly, the third graph has no correlation. Correlation does not imply causation. We can't imply that hair has anything to do with shoe size because there could be other variable affecting the data.

S.A (4th period)

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Mr. C

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