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Concatenating rows with the chi squared test and continuity corrections.

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asked May 17 in BUS 3018F - Models by anonymous

In some solutions, they combine the two rows when the expected observations are less than 5 and in some they don't. The same applies with the continuity correction when using the normal approximation on other tests. I would just like to know what is expected of us with regards to that. Thanks.

1 Answer

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answered May 17 by Coetzee.Marais (150 points)

A continuity correction is made when we use a continuous distribution as an approximation to a discrete distribution, or the other way around.

For example, when we approximate the binomial (alive-dead) model with the normal distribution.

Page 18 of chapter 10 gives a good explanation of this, and also the example starting at the bottom of page 31 of the same chapter. On page 34  (same chapter) there is a good example of when the continuity correction will not be made (i.e. when it will have no real effect.)

When it comes to grouping ages with less than 5 expected deaths, one should especially do this when there are more than one age group with expected deaths less than 5.