1.Summary Descriptive Statistics.Answer all parts of this question.Consider the following 20 midterm grade scores in a Statistics class. 39 92 75 614587595187128937416323987124750

a)Calculate the mean, median and mode for these observations.

b)Calculate a trimmed mean for these observations.

c)Calculate the standard deviation and variance for these observations.

d)Calculate the first, second and third quartiles for these observations.