How strongly do physical characteristics of sisters and brothers correlate? here are data on the heights (in inches) of 11 adult pairs:8?

Question

How strongly do physical characteristics of sisters and brothers correlate? here are data on the heights (in inches) of 11 adult pairs:8?

0

Answers ( No )

    0
    2021-11-25T22:03:23+00:00

    Answer: moderate (r = 0.516).

    These are data on the heights (in inches) of 11 adult pairs, that you forgot to include with your question:

    Brother   
    71 
    67 
    66 
    70 
    70
    71 
    70 
    73 
    72 
    65 
    66



    Sister     
    69 
    64  65 
    63 
    65  62 
    65 
    64 
    66 
    59 
    62

    The strenght of the correlation of two variables can be determined by the correlation coefficient, r.

    A perfect positive correlation has r value equal to 1.

    A perfect negative correlation has r value equal to – 1.

    A correlation coefficient r between 0.7 and 1 shows a strong correlation.

    A coefficiaent around 0.5 is moderate, and a coefficient whose absolute value is below 0.3 is weak.

    You have to use a graphing calculator, a worksheet program, or a special program to calculate this statistics.

    I used Excel and obtained r = 0.516. So, that shows a moderate correlation.

    To use Excel’ tools to calculate r, follow these steps:

    1) Enter the data for brothers is a colum and the data for sisters in the colum next to brother’s.

    In this way:



    Brother
    Sister



    71        
    69



    67        
    64



    66        
    65



    70        
    63



    70        
    65



    71        
    62



    70        
    65



    73        
    64



    72        
    66



    65        
    59



    66        
    62


    2) Select all the data (you may or may not include the name of the variables)

    3) Go to the main bar and choose insert

    4) Go to the main bar and choose graph, dispersion

    That will show the points in a scatterplot.

    5) Change to the version of the graph that contains the line joining the dots and the formulas for y and r^2

    6) calculate r as the square root of r^2.

    I got r^2 = 0.2667, from which r = 0.5164

Leave an answer

Browse
Browse