statistics 1

An Example of a Report Date :

To :

From :

R E : Analysis of Buena School Dist ri ct Bu s Data

Per your request , I have prepared an analysis of the Buena School District Bus Data with respect to . the maintenanc e cost for last month . The following questions will be answered throughout the re port .

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Around what values do the data tend to cluster?

What was the mean maintenance cost last month?

What was the median cost? •

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Is one measure more representative of the typ ical cost than the other?

What is the range of the maintenance costs?

What is the standard deviation (i.e ., the variation or spread in the data)?

About 95 percent of the maintenance costs are between what two values?

Please contact me if there is any additional information needed .

A nalysis

Last month , the Buena School District provided maintenance on 80 veh icles , which totaled $36 ,023 .00 . The maintenance was for passenger vehicles that ranged from 6 passenge rs to 55 passengers in size and had been in use from 1 to 14 years . The miles traveled by the vehicles ranged from 700 to 1,000 miles and each vehicle used either gasoline or diesel fuel.

The purpose of this report is to analyze the maintenance cost for the last month . The resu lts of the analysis follow :

• Th e data tend to cluster around the $400 range . The mean of the data is $450 a nd the median of the data is $456. The median of the data appears to be more representative of the typical cost than the mean due to the fact that the data are not symmetrical when plotted .

• The range o~ ~ aintenance c~sts is $241 _, since the smallest cost is $329 and the largest cost is $570. The vanatIon or spread in the data 1s $53 .68 . About 95% of the maintenance costs are between $438 and $462 .

The output on wh ich th is report is based is found in the Append ix . If additional information o r clarification is needed , please feel free to contact me .

APPENDIX : Analysi s of School Bu M ·

s ain te nance Cost (Excel Documen tation ): Descri ptive Statistics:

Maintenance

M ean

Stan d ard Error Med ian

Mode

St andard Deviation Sample Variance Kurtosi s

Skewness Range Minimum Maximum Sum Count Confidence Level (95 .0%)

Diagram of Data:

20 18

16

14

?! 12 ~ 10 ... G> a. 8

6

4

2

0

450.2875 6.002273

456 329

53 .68596 2882 .182 -0 .15416 -0 .16106

241 329 570

36023 80

11 .94722

Histogram

n,rf' ,f' n,el n,t§) b,.<S' b,.rf' b,.i' ~el ~t§) 'o~ ~~ <$' 'or£) 'oc§> Maintenance

Computations/Calculations:

95% of maintenance costs (rounded to the nearest dollar): 4 50 - 12 to 4 50 + 12 is $4 38 to $462.