(HW_3_1) The following table represents the lengths, in terms of
number of characters, of 100 English words randomly chosen from a
dictionary. Construct the frequency table and compute the average length
of an English word using two ways (the raw data and the frequency of occurrence).
Calculate the standard deviation of the word lengths from the mean. Using
these estimates draw the histogram representing the data distribution.
3
2
2
4
4
4
3
9
9
3
6
2
3
2
3
4
6
5
3
4
2
3
4
5
2
9
5
8
3
2
4
5
2
4
1
4
2
5
2
5
3
6
9
6
3
2
3
4
4
4
2
2
4
2
3
7
4
2
6
4
2
5
9
2
3
7
11
2
3
6
4
4
7
6
6
10
4
3
5
7
7
7
5
10
3
2
3
9
4
5
5
4
4
3
5
2
5
2
4
2
(HW_3_2) Suppose that X~ Normal(m=3,
s=4)
compute the corresponding standard
Z-scores for the following numbers, state how many SD's
is each of these numbers aways from m, and calculate the area under the
distribution curve on the
given interval:
-5, [-5 : 5]
11, [-infinity : 11]
5, [5 : infinity]
1.4, [0 : 1.4]
What is the probability P(-3<X<-1)? Is it different from P(-3<=X<=-1)?
Why?
\Ivo D. Dinov, Ph.D., Departments of Statistics and Neurology, UCLA
School of Medicine/