STATISTICS notes

STATISTICS notes - o Tally observations into appropriate...

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STATISTICS NOTES FOR 09-06-07 T Relative Frequency Table o Increased sample sizes require data to be condensed o Advantage: summary table of data arranged into numerically ordered class groupings o Disadvantage: value of individual observations are lost through the grouping process. T Relative Frequency Calculation: o = Frequency divided by total count o Expresses as a proportion or percent independent of the size of the data set o Used when comparing two data sets of different size o Used for comparing yearly data or organizational data. T Frequency Table Construction: o Determine number of classes: 5 to 15 o Determine the width of class intervals – range / (number of classes -1) o Establish the bounderies of the class o EX: 47-8 o (5 - 1) = 9…. . = 10 FREQ. REL. FREQ. CUMU. FREQ. 0 < 10 1 1/14 0.071 1 10 < 20 3 3/14 0.214 4 20 < 30 6 6/14 0.429 10 30 < 40 3 3/14 0.214 13 40 < 50 1 1/14 0.071 14 T F T Construction o Classes must not overlap o Must include the entire rage of observations o Choose to facilitate interpretation
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Unformatted text preview: o Tally observations into appropriate classes o Total the frequency for each class o Calculate the relative frequency for each class T Histogram o Vertical bar chart that are constructed at the boundaries of each class o Bars are the same width o Joined at the class boundaries o Height represents the frequency or the relative frequency of each category T Five-Number Summary o Minimum value of an ordered data set o Q 1 = upper boundary of first quarter of data – quartile one o Median = middle value of ordered data – quartile two o Q 3 = upper boundary of third quarter of data – quartile tree X min 2.37 Q 1 2.72 Median 3.11 Q 3 3.52 X max 4.00 T Box plot o If extreme outlying values exist, they can be graphed as separate points beyond the ends of the whiskers that extend to the lowest and highest values that are not outliers. Range = x max – x min IQR = Q3 – Q1 (just the box length)...
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This note was uploaded on 04/14/2008 for the course STAT 2160 taught by Professor Heun during the Fall '08 term at Western Michigan.

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STATISTICS notes - o Tally observations into appropriate...

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