ECON 245 FINAL REVIEW
Topic One:
Descriptive Statistics:
ways of conveying or presenting statistical information efficiently and
effectively
Inferential Statistics:
used to assist with decision making when faced with
problems?
Population:
all the valued items that may be of interest
Sample:
A selected number of the population items
-We are trying to infer something about the general population from the specific sample results.
-Process involves uncertainty which we can measure/quantify in order to judge the quality of our
inferences.
Population has no uncertainty whereas a sample has uncertainty.
Mean:
the average
Range:
the difference between the maximum and minimum numbers
We typically work with a sample rather than a population because a population is typically very
large, part of it may be inaccessible, and the measurement may be destructive.
-Individual sample statistics are called sample statistics
-Any function of sample statistics is also a statistic
-Sample statistics characterize the feature of a sample in the way that parameters characterize
a population
-Sample statistics can misinterpret figures, have misleading comparisons, mixed reliability, or an
inadequate title.
Frequency Distribution:
a way of summarizing a large set of tabular data.
-Divide values into intervals and report the frequency of occurrence of values in each interval
(i.e. Group by frequency of occurrence)
Relative Frequency:
the frequency in each class relative to the total number of observations
-determined by dividing the frequency of each class by the total number of observations and
expressing it as a decimal.
-SUMS TO ONE.
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Cumulative Frequency:
is the sum of the absolute frequencies from lowest class to the highest
class
Histogram:
the classes are plotted on the horizontal axis and the frequency of each class is
plotted on the vertical axis
-also known as bar graph
Frequency Polygon:
constructed by drawing a straight line between the midpoints of adjacent
class intervals
-has similar set up as histogram
Ogive:
similar to frequency histogram, and connects the corner points which smoothes the
histogram
Topic Two:
Central tendency:
commonly used parameters for interpreting and understanding the meaning
of values in populations.
-
Mode:
the value that occurs most often
The mode may not be near the centre and there can be more than one mode in a data set.
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- Fall '10
- Franz
- Normal Distribution, Interest, Probability distribution, probability density function, Continuous probability distribution
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