Download Vocab - Pierce College

Vocab
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Normal, Standard Normal, Uniform, t
Point Estimate
Sampling distribution of the means
Confidence Interval
Confidence Level / α
Chapter 5 main problem types
• Given one individual, find the probability
they are less than / greater than / between
value(s)
• Given a sample, find the probability the
sample mean is less than / greater than /
between value(s)
• Given a probability, find a cutoff value or
sample mean so the given probability is
above or below that cutoff value
Examples
Men’s weights are normally distributed with a
mean of μ=68in, σ=2.2in.
• Find the probability that a man chosen
at random will be between 64 and 70in
tall
• If 16 men are sampled, what is the
probability that their mean height will be
less than 66in?
• I am taller than 98.84% of men. How
tall am I?
Chapter 6 main problem types
• Find a confidence interval for a proportion
(percentage), given a sample size and either
the sample proportion, or x (number of
successes in the sample)
• Find a confidence interval for a mean,
(usually σ unknown), given a sample size,
either the sample mean or the sample data,
and a standard deviation
• Interpret the confidence interval
Examples
• 400 people are surveyed. 80 indicate they
have a cat. Find a 95% confidence interval
for the percent of the population who own
cats.
• 51 students are asked how many hours they
work a week. The sample showed a mean
of 28 hours, with a standard deviation of 6
hours. Find a 99% confidence interval for
the true mean hours worked by students.
More minor problem types
• Determine sample size given desired margin
of error
• Find critical value given a confidence level
other than 90%, 95%, 99% (z-only)
Review Exercises
Chapter 5: 1, 2
Chapter 6: 1, 2, 3