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Objectives |
| Essential Question:
Does all data fit a bell curve? |
The Normal Distribution
- Define density curve.
- Models the a distribution
- Above horizontal axis
- Area under it = 1
- Area under part of the curve = probability
- Describe the normal distribution.
- Symetrical
- Bell Shaped
- Range negative infinity to positive
infinity
- Be as one with the 68-95-99.7 Rule
for normal distributions.
Note:
in the 1st part of the test for this chapter, you will not be permitted to use calculators or
tables. The entire test will be based on the above rule.
- Be as one with the
0-75-89 Rule for any distribution.
Note: this is the worst case situation for any distr.
- Chebyshev's Rule: p = (1 - 1/k^2)
- State where the 2 inflection points
fall on a normal distribution. This will help you draw the norm. distr.
- Correctly use N(mean, sigma) notation.
- State the effects on a normal distribution
of increasing standard deviation.
- According to the normal distribution,
what is the probability of obtaining an exact value for a data point.
Homefun: prob. 2.3, 2.5, 2.7, 2.9
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Activities |
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- Lesson 1
- Key Concept: What is a normal distribution?
- Purpose: Lay the foundation for using the normal
distribution.
Interactive Discussion:
Objectives. Explain why the
68-95-99.7 Rule is
critical for developing "normal distribution intuition".
Seat Work: Use the empirical rule
to find various areas under the n-distribution.
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| Essential Question:
What does the area under the "bell
curve" mean? |
Finding Areas Under the Normal Distribution
- Calculate z-scores.
- z = distance from mean in std dev units
- Estimate the probability of obtaining
a range of values by using the normal distribution. (find the area under the
curve)
Probability = area under curve
- Find
z-scores corresponding to Q1 &Q3 of a box and whiskers plot for normally
distributed data.
- Using a normal distribution, estimate a critical
value given the probability of finding a value as extreme or more extreme (a
tail area).
- Judge the normality of a distribution by examining
histograms, stem plots, dot plots, or box and whiskers plots.
- Bell shaped
- Symmetrical
- 68-95-99.7 Rule
- Judge the normality of a distribution using a normal quantile plot on a TI-83.
Homefun: prob. 2.12, 2.13, 2.17
- Work quality control reject rate problems.
- Convert a normal distribution into a
cumulative frequency
plot.
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- Lesson 2
- Key Concept: Area under
the normal distribution and how it relates to a box and whiskers
plot.
- Purpose: Understand when
a data set is normally distributed.
Interactive Discussion:
Objectives
2-person teams: Derive an equation
for the z-score
Seat Work: Find the area under n-distribution using tables
and the TI-83 calculator.
2-person teams:
- Derive the z-scores of Q1, Q2,
LL, UL
- Draw a box and whiskers diagram
of an n-distribution
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