Individualproject
1. Herearethesalariesof24ITprofessionalsin 2009in Chicago:
|
$109,000 |
$65,000 |
$65,000 |
$59,000 |
$180,000 |
$101,325 |
$130,000 |
|
$95,000 |
$81,500 |
$69,000 |
$71,500 |
$74,880 |
$64,000 |
$72,000 |
|
$71,000 |
$82,300 |
$49,000 |
$51,200 |
$39,000 |
$48,500 |
$64,330 |
|
$41,100 |
$52,330 |
$82,000 |
|
|
|
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a. Makeafrequencydistribution using fiveclasseswiththeupperclasslimit of thefirstclassasthe lower classlimitof thesecond.
b. Makeahistogramfromyour frequencydistribution.
2. Find thepricesof10 different printersforyourPC.Computethemean,median andmodeof theseprices.
3. Inthefollowingtable youcan seethe MemoryUsageata givenmomentof aPC computer. a. Find themeasuresoftendencyand themeasuresofdispersionofthememoryusageinKb.
b. Onceyoucompletethecomputationof themeasures, completeascatterplotof thosevalues.
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c. Identifythe valuesthatareresponsibleforthevariance ofthedataset,giveapossible solutionon howthecomputer usercould decrease hisMemoryusagevariance.
4. Thereisamathematical theorycalledqueuingtheorythat studiesways inwhich computerjobs are fed inCPUsandresearches on howthesecanbereducedtoaminimum. Showhowcana computerestimatetheaveragenumberofjobswaiting ataqueue?
Supposethatina5secinterval jobs arriveas indicatedinthefollowingtable(Arrival timeis assumedto beatthe beginning ofeachsecond)Inthefirstsecondjobs AandBarrive.During the second secondB movestotheheadof theline(Ajob iscompleted asittook1sectobe served), andCandDjobsarriveandso on.
Find:
a. Themeannumberof jobsin line
b. Themodeof thenumberof jobs in line
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Timeinseconds |
Jobs |
|
1 |
A,B |
|
2 |
C,D |
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3 |
|
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4 |
E,F |
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5 |
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5. Manytimes,wearerequired to usestatisticalmeasurestotryand constructa problem.
Werun aprogramfora10differentinputs. Thetimesaremeasures in 1–second intervalsand noneof them took0secs.
a. Supposethestandarddeviationof a setoftimeswerun theprogramis0. What doesthistell
you aboutthe running times?
b. Supposethatthemeanof thetimesis1000.9secwhilethemedianis1sec. Explain whatdoyou knowabouttheprogramrunningtimesfor all10differentinputs?
c. Assume nowthatthemeanof thetimesis1000.9secwhilethe medianis1secand the varianceis9998000.Explainwhatdo youknowabouttheprogramrunningtimesforall 10 differentinputs
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