Curriculum
Course: Statistics — Third Secondary
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Curriculum

Statistics — Third Secondary

Unit 1: Correlation and Regression

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Unit 2: Advanced Statistical Measures

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Unit 3: Probability

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Unit 4: Random Variables

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Unit 5: The Normal Distribution

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Text lesson

The Normal Distribution and Its Applications

Statistics — Third Secondary

The Normal Distribution and Its Applications

Common mistakes

Common mistakes

Comparison aspectMain ideaKeywords
Forgetting to convert X to Z
  • the table is for the standard normal distribution only
  • so it is used with X only after conversion
tablestandardnormaldistribution
Subtracting from 0.5 when the area is between two positive valuesin that case we subtract the two table areas from each othercasetableareas
Forgetting symmetry
  • P(Z ≤ −a) = P(Z ≥ a)
  • so the table does not need negative values
tabledoesneednegative
Mixing up the standard deviation and the variance in the conversion
  • we divide by σ
  • not by σ²
divide
Giving a probability without converting it to a percentage
  • when a question asks for a percentage
  • multiply the probability by 100
questionasksmultiply
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