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Mathematics & Statistic Tutor Perth - SPSS Help   

The Confidence Interval
Check that you really understand which value of Z you choose, remember that you have two areas that add to
 100% - confidence level!
 

Tests of Significance or Hypothesis Testing

I have now stated to tell my students to write in a slightly new order only to stop mistakes in the Hypotheses and only in basic Statistics courses at College so

Assumptions / Definitions

Test Data

Hypotheses

Test Statistic

P-value

Decision

Conclusion

Test Data, whatever you write here number or symbol will never appear in the Hypotheses. 
The same number appears in both Null and Alternative hypothesis

Always draw a diagram and then you can check whether z should be positive or negative before you use the formula for the Test Statistic. Often people get the top the wrong way around!

Once you have decided to either reject or do not reject the Null Hypothesis.

A little trick to check whether the p-value is bigger or smaller than the level of significance. Put both values to the same number of places and then cross out all the zeros from left to right and then compare the numbers.

Example

p-value = 0.023    Level of Significance = 0.05

              p-value             Level of Significance  

              0.023               0.05

              0.023               0.050

              0.023               0.050

              23    is less than  50

              p-value      <       Level of Significance  

Create your own “ reject / do not reject ” statements and just adapt to each question