Reference no: EM1319023

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

 

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

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