Establish the mean and median.
Consumer Review posts reviews and ratings of a variety of products on internet. The following is a sample of 20 speaker systems and their ratings (www.audioreviews.com). The ratings are on a scale of 1 to 5, with 5 being the best
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Speaker
|
Rating
|
|
Infinity Kappa 6.1
|
4
|
|
Allison One
|
4.12
|
|
Cambridge Ensemble II
|
3.82
|
|
Dynaudio Contour 1.3
|
4
|
|
Hsu Rsch. HRSW12V
|
4.56
|
|
Legacy Audio Focus
|
4.32
|
|
Mission 73li
|
4.33
|
|
PSB 400i
|
4.5
|
|
Snell Acoustics D IV
|
4.64
|
|
Thiel CS1.5
|
4.2
|
|
ACI Sapphire III
|
4.67
|
|
Bose 501 Series
|
2.14
|
|
DCM KX-212
|
4.09
|
|
Eosone RSF1000
|
4.17
|
|
Joseph Audio RM7si
|
4.88
|
|
Martin Logan Aerius
|
4.26
|
|
Omni Audio SA 12.3
|
2.32
|
|
Polk Audio RT12
|
4.5
|
|
Sunfire True Subwoofer
|
4.17
|
|
Yamaha NS-A636
|
2.17
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a. work out the mean and the median.
b. calculate the first and third quartiles.
c. figure the standard deviation
d. The skewness of this data is -1.67. Comment on the shape of the distribution.
e. What are the z-scores associated with Allison One and Omni Audio?
f. Do the data contain any outliers? Describe