Answer:
From the given information, the ten observations data on October snow cover for the Eurasia during a year is,
6.5 12.0 14.9 10.0 10.7 7.9 21.9 12.5 14.5 9.2
For the given data, 21.9 is an outlier, so trimmed mean would be good choice for the researcher.
Remove the smallest and the largest values to compute the trimmed mean.
[tex]x_{ir(10)}[/tex] = (12.0 +14.9 +10.0 +10.7 + 7.9 +12.5 +14.5 + 9.2) / 8
[tex]x_{ir(10)}[/tex] = 91.7 / 8
[tex]x_{ir(10)}[/tex] = 11.4625