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Sintering Variation

Objective: Determine the correlation of a
     Green Dimn.ws Sinter Dimn.
                  (or)
    Green weight ws Green Dimn.
Scatter Plot
• A scatter plot is a graph of a collection of
  ordered pairs (x,y).

• The graph looks like a bunch of dots, but some
  of the graphs are a general shape or move in a
  general direction.
The Coefficient of Correlation
• Measures the relative strength of the linear
  relationship between two variables (denoted by
  r) and Unit-less
• Ranges between –1 and 1
• The closer to –1, the stronger the negative linear
  relationship
• The closer to 1, the stronger the positive linear
  relationship
• The closer to 0, the weaker any positive linear
  relationship
Scatter Plots of Data with
            Various Correlation Coefficients
    Y                                           Y                                            Y




                                         X                                          X                  X
                 r = -1                                      r = -.6                             r=0
                                                                                             Y
  Y                                              Y



                                         X                                            X                X
                 r = +1                                       r = +.3                            r=0
Slide from: Statistics for Managers Using Microsoft® Excel 4th Edition, 2004 Prentice-Hall
Positive Correlation
• If the x-coordinates and the
  y-coordinates both
  increase, then it is
  POSITIVE CORRELATION.
• This means that both are
  going up, and they are
  related.
No Correlation
• If there seems to be
  no pattern, and the
  points looked
  scattered, then it is no
  correlation.

• This means the two
  are not related.
Negative Correlation
• If the x-coordinates and the y-
  coordinates have one
  increasing and one
  decreasing, then it is
  NEGATIVE CORRELATION.
• This means that 1 is going up
  and 1 is going down, making
  a downhill graph. This means
  the two are related as
  opposites.
The Coefficient of Determination

 The coefficient of determination (denoted by R2) is a key
output of regression analysis

•The coefficient of determination ranges from 0 to 1.

•An R2 of 0 means that the dependent variable cannot be
predicted from the independent variable.

•An R2 of 1 means the dependent variable can be predicted
without error from the independent variable.

•An R2 between 0 and 1 indicates the extent to which the
dependent variable is predictable
Scatterplots
     Which scatter plots below show a linear trend?
          No
a)    Correlation         c)       Negative      e)
                                   Correlation

                                                          Positive
                                                          Correlation


     r = -0.9&R2=0             r = -1&R2=1            r = 1&R2=1
                     f)

                               Constant
                               Correlation

                           r = 0&R2=0
Interval Estimates
        for Different Values of x
         Prediction Interval
         for an individual y,
y        given xp


                                         Confidence
                                         Interval for
    ∧      + b 1x                        the mean of
    y = b0                               y, given xp




                                              x
                                x   xp
Sintering Machine Variation
Green Part weight ws Green Part Dimn.



Coefficient of Determination is
0.1882%(0.001882)&Coefficient
of Correlation is-4.33% (-0.0433)
that means No Correlation
Green Part Dimn.& Sinter Part Dimn.



Coefficient of Determination is
20.367%(0.2036)&Coefficient of
Correlation is 45.12% (0.4512)
that means Positive Correlation
Green Part weight & Sinter Part Dimn.



Coefficient of Determination is
2.451%(0.0245)&Coefficient of
Correlation is -15.45% (-0.1545)
that means No Correlation
Green Part weight ws Green Part Dimn.



 Coefficient of Determination is
 0.289%(0.0245)&Coefficient of
 Correlation is -5.37% (-0.537)
 that means No Correlation
Green Part Dimn.& Sinter Part Dimn.



Coefficient of Determination is
9.053%(0.9053)&Coefficient of
Correlation      is   -30.089%
(-0.30089) that meansNegative Correlation
Sinter Part Dimn & Green Part weight



Coefficient of Determination is
14.495%(0.14495)&Coefficient
of Correlation is -38.0734%
                     Constant Correlation
(-0.380734) that means