1. In a survey, 24 IT professionals in Chicago were asked how much their annual

1.      In a survey, 24 IT professionals in Chicago were asked how much their annual salary was for the year 2012. The results are shown below:

$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    $52,300      $82,000

a.      Construct a frequency distribution with 5 classes.

b.      Create a histogram of the data using the frequency table from question 1 –a.

2.      A software company asked 100 of its programmers to develop a certain program individually. The following histogram shows the time it takes a programmer to finish the task

a.      How many classes are there for the given histogram?

b.      What is the class width of the histogram?

c.       What percentage of programmers can complete the task in 30 hours?

d.      How many hours does it take the majority of the programmers to complete the task?

    3.Search the internet for prices of 11 different laptops.

            a. Compute the mean, median, and mode of these prices.

            b. Find the first and third quartiles of the prices.

4. In the following image, the memory usage of various processes of a computer running a Windows Operating System is shown:

o   Create a scatter plot of the memory usage of the processes.

o   Find the following measures of central tendency of the memory usage in Kilobytes (Kb):

§  Mean

§  Mode

§  Median

o   Find the following measures of dispersion of the memory usage in Kb:

§  Range

§  Variance

§  Standard Deviation

o   Identify the values that are responsible for the variance of the dataset. Provide a possible solution on how the computer user could decrease the variance of his or her memory usage.

       5.Answer the following questions completely, using proger grammar, complete sentences, and correct terminology:

a.      Explain what it means to have a standard deviation of 0.

b.      Without doing an calculations, is it possible to tell which of the following 2 sets has a higher standard deviation? Explain your answer.

§  Set 1= (1,2,3,4,5,6,7,8)

§  Set 2= (2,4,6,8,10,12,14,16)