Question

The most frequently used measures of central tendency for quantitative data are the mean and the median. The following table shows civil service examination scores from 24 applicants to law enforcement jobs: 83 74 85 79 82 67 78 70 18 93 64 27 93 98 82 78 68 82 83 99 96 62 93 58 Using Excel, find the mean, standard deviation, and 5-number summary of this sample. Construct and paste a box plot depicting the 5-number summary. Does the dataset have outliers? If so, which one(s)? Would you prefer to use the mean or the medianas this dataset’s measure of central tendency? Why?

Answer 1

#by using Excel function:

=AVERAGE(O1:O24)

The mean=75.5

=STDEV(O1:O24)

standard deviation=19.99

Min=18 # by using Excel function: =MIN(O1:O24)

Max=99 # by using Excel function:=MIN(O1:O24)

Q1=67.75#by using Excel function:=QUARTILE(O1:O24,1)

Q2=80.5 # by using Excel function:=QUARTILE(O1:O24,2)

Q3=87 #by using Excel function:=QUARTILE(O1:O24,3)

since median is a positional average it is least affected by an extreme observations.