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$3

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      a.    Makeafrequencydistribution using fiveclasseswiththeupperclasslimit of thefirstclassasthe lower classlimitof thesecond.b.   Makeahistogramfromyour frequencydistribution.
   2.   Find thepricesof10 different printersforyourPC.Compu
tethemean,median andmodeof theseprices.3.   Inthefollowingtable youcan seethe MemoryUsageata givenmom
entof aPC computer. a.    Find themeasuresoftendencyand themeasuresofdispersionofthememoryusageinKb.b.   Onceyoucompletethecomputationof themeasures,  completeascatterplotof thosevalues.
  c.     Identifythe valuesthatareresponsibleforthevariance ofthedataset,giveapossible solutionon howthecomputer usercould decrease hisMemoryusagevariance.

4.   Thereisamathematical theorycalledqueuingtheorythat studiesways inwhich computerjobs are fed inCPUsandresearches on
howthesecanbereducedtoaminimum. Showhowcana computerestimatetheaveragenumb
erofjobswaiting 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

3 

5 

5.   Manytimes,wearerequired to usestatisticalmeasurestotryand constructa problem.

Werun aprogramfora10differentinpu

ts. Thetimesaremeasures in 1-second intervalsand no
neof them took0secs.

a.    Supposethestandarddeviationof a setoftimeswerun theprogramis0. What doesthistell

you aboutthe runn
ing times?

b.   Supposethatthemeanof thetimesis1000.9secwhilethemedianis1sec. Explain whatdoyou knowabouttheprogramrunningtimesfor all10differentinputs?

c.     Assume nowthatthemeanof thetimesis1000.9secwhilethe medianis1secand the varianceis9998000.Explainwhatdo youknowabouttheprogramrunningtimesforall 10 differentinputs

Individualproject

1. Here are the salaries of 24 IT professionals in 2009 in 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

a. Make a frequency distribution using five classes with the upper class limit of the first class as the

lower class limit of the second.

b. Make a histogram from your frequency distribution.

2. Find the prices of 10 different printers for your PC. Compute the mean, median and mode of

these prices.

3. In the following table you can see the Memory Usage at a given moment of a PC computer.

a. Find the measures of tendency and the measures of dispersion of the memory usage in Kb.

b. Once you complete the computation of the measures, complete a scatter plot of those values.

c. Identify the values that are responsible for the variance of the dataset, give a possible solution on

how the computer user could decrease his Memory usage variance.

4. There is a mathematical theory called queuing theory that studies ways in which computer jobs

are fed in CPUs and researches on how these can be reduced to a minimum. Show how can a

computer estimate the average number of jobs waiting at a queue?

Suppose that in a 5 sec interval jobs arrive as indicated in the following table ( Arrival time is

assumed to be at the beginning of each second) In the first second jobs A and B arrive. During

the second second B moves to the head of the line ( A job is completed as it took 1 sec to be

served), and C and D jobs arrive and so on.

Find:

a. The mean number of jobs in line

b. The mode of the number of jobs in line

Time in seconds Jobs

1 A,B
2 C,D

3

4 E,F

5

5. Many times, we are required to use statistical measures to try and construct a problem.

We run a program for a 10 different inputs. The times are measures in 1-second intervals and none of

them took 0 secs.

a. Suppose the standard deviation of a set of times we run the program is 0. What does this tell

you about the running times?

b. Suppose that the mean of the times is 1000.9 sec while the median is 1 sec. Explain what do you

know about the program running times for all 10 different inputs?

c. Assume now that the mean of the times is 1000.9 sec while the median is 1 sec and the

variance is 9998000. Explain what do you know about the program running times for all 10

different inputs