Review Session
STAT 226
POPULATION, PARAMETER, STATISTIC, SAMPLE
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Which goes with which?
POPULATION, PARAMETER, STATISTIC, SAMPLE
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You are looking at the average age of all
American alligators, you select 15 alligators off
the coast of Florida and track them to see how
old they become. The average of these 15 live
to be 12. The true average age alligators live to
is 16.
POPULATION, PARAMETER, STATISTIC, SAMPLE
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Your dog can jump 2.5 feet. This leads you to
believe your dog can jump farther than any
other dog. However, the American record book
has a dog that can jump 6.48 feet.
POPULATION, PARAMETER, STATISTIC, SAMPLE
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The Iowa state football team has an average
height of 6’2”. The NCAA average height for
football players is 6’. You then conclude the
ISU team is pretty tall.
POPULATION, PARAMETER, STATISTIC, SAMPLE
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Oak trees live to be an average age of 263
years. The oak trees in America have been
known to live an average of only 123 years.
CATEGORICAL OR QUANTITATIVE
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Categorical :
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Quantitative:
CATEGORICAL OR QUANTITATIVE
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Top 10 websites
Number of roll – over car accidents based on car brand
The baggage fees for different airlines collected each
year
Price of cars people purchased in 2008
Regional rain fall
sales for 4 types of smart phones
Height of 200 random people in Iowa
Net Income
Wine exports of the top 5 wine-exporting countries
CATEGORICAL OR QUANTITATIVE
Histogram
 Bar Graph
 Pie Chart
 Box Plot
 Pareto Chart
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CREATE A VISUAL
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The following table presents the sales of cars in
the US broken down by manufacturer
Manufacturer
Car Sales
Chrysler
107,172
Ford
166,441
General Motors
180,402
Honda
83,925
Nissan
85,182
Toyota
137,960
10 9 8 4 2 8 9 5 8 6 7 8 3
a)
b)
c)
d)
e)
What is the sample size
Find the median
Find the IQR
Find the mean
The standard deviation in 1.38, what is the
variance?
NUMBER SUMMARIES

When is the 5 number summary used over the
mean and standard deviation?
Car prices
b) What is an advantage to having them side
by side?
Honda
a) What is this graphic called?
c) Give the 5-number summary for Honda
Price (in 1000s)
62
d) What is the shape of the distribution of
Nissan?
Nissan
83
64
43
38
35
25
24
23
16
e) For which of the two distributions do you
expect the corresponding mean to be closer
to the median?
f) Compare and contrast both distributions
regarding their overall shape, center, spread
and For the center and spread do not simply
state the numerical values but explain how
they compare for both dealerships
NORMAL DISTRIBUTION
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What is the empirical rule tell you?
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What is the equation relating Z-score to Mean,
standard deviation, and your value of X?
SWIM TEAM TIMES
The times for the 100m freestyle for the womens swim team is evenly distributed with a
mean of 59.6 sec. and a standard deviation of 1.2 seconds.
a)
b)
c)
d)
e)
What time can 50% of the teammates complete a 100m freestyle
in?
What percent of swimmers can complete a 100m freestyle
between 58.4 seconds and 60.8 seconds.
Jane brags that she can swim the race faster than 97.5% of her
teammates? What would her time be?
If Jenny is wanting to make the team and she can swim a 100 m
freestyle in 61 seconds, do you think she would make the team?
What is the probability that one of the girls will beat the opponents
fastest swimmer that can swim a 100 m freestyle in 56 seconds?
Z-SCORE

What does a z-score tell you?
USING Z SCORES
P (Z < 1.5)
b) P(Z < z) = 0.35
c) P (Z > - 1)
d) P (|Z| < 1.2)
e) P(Z > z) = 0.60
f) P (Z > 0.5)
g) P (-1 ≤ Z ≤ 1.5)
h) P(-z < Z < z) = .78
a)
BOX OFFICE SALES
Opening weekend, Marvel films gross sales are normally distributed making an average of
$68,326,910 and a standard deviation of $22,442,000.
a)
X-men only made $55,101,604, how many standard deviations
does this movie fall from the mean.
b)
Thor: The Dark World had an opening box office sales of
$85,737,841. What percentile does Thor2 fall under
c)
The Avengers made $207,438,708. What percentile does this fall
under
d)
If the new spiderman is hoping to hit at least the 40th percentile,
how much money is it expecting to make opening weekend in gross
sales?