Thread: analyzing the scatter plot

Hi.
I'm trying to analyze the scatter plot..
There are three data that i had to use for this question: height, gender and right hand span

From the given data, i obtained, I found the correlation between height and right hand span for the group as a whole is: 0.556

Then, I had to produce a scatter plot for: height vs right hand span (please refer to attachment).

From this graph, I need to make a comment on the relationship between height and right hand span, for the group as awhole. Does the relationship depend upon gender?

Can anyone help me with it? please explain in detail..since i don't really have clue..

Thanks

The correlation will always have values between -1 and 1. The closer to either of -1 or 1 the value is the more there is evidence of a strong relationship between the 2 groups. So, the closer the correlation is to 0, the less of a relationship between the 2 groups. Correlation of 1 indicates that there is a positive correlation - ie: when the values of 1 group increase, the values of the other group increase or if 1 decreases then the other tends to decrease too. A correlation of -1 is the opposite - that is: when 1 group increases, the other decreases and vice versa.
A value of 0.556, as u can see from the scatter plot, indicates that the values are indeed somewhat related. The closer to 1 the correlation is, the closer to a straight line the scatter plot will be. So, in conclusion, there is enough evidence to warrant doing more tests to between these 2 groups.

Hi Thanks for your help.
I have another question that i need help.

The question is: (data was given for gender and speed)
Produce an appropriate graph to determine if it is reasonable to assume that the speeds,for each gender, can be modelled by a normal distribution. Comment on what your graphs suggest.

So I draw a graph(I think is appropriate for this question)- normal distribution



Now, I need to make a comment based on the graph.
Can I say: since most data are within the 95% interval line, the data is normally distributed??? or not?

Please help