Download HW Solutions for STT 351: Calculating Statistics from Data Sets - Prof. Nao Mimoto and more Study notes Probability and Statistics in PDF only on Docsity!
STT 351 HW on Ch 1
Due: Jan 19 (Thursday)
0.1 Questions:
- The accompanying data are specific gravity values for various wood types used in
construction.
Obtain the following by hand (using calculator not Matlab):
(a) size of the sample.
n = 15
(b) Sample mean X and sample median
X.
X = .44,
X =. 42
(c) Sample variance S
2
, sample standard deviation S.
S = .081, S
2 =. 0066
(d) 1st, 2nd and 3rd sample quartile.
Q
1
= .39, Q
2
=. 42 Q
3
(e) histogram of the data.
(f) Box plot of the data. Do we have outliers?
- From class web page, download the dataset ex01-013.xls. The dataset constains the
measurement of tensile ultimate strength (ksi). Obtain the following by using Matlab,
and Attach the printout of the histogram and boxplot.
(a) size of the sample.
n = 15
(b) Sample mean X and sample median
X.
X = 134.9,
X = 135
(c) Sample variance S
2 , sample standard deviation S.
S
2
= 20.6, S = 4. 54
(d) 1st, 2nd and 3rd sample quartile.
Q
1
= 132.75, Q
2
= 135 Q
3
(e) Plot histogram of the data with default bin width. Describe the overall shape.
(f) Plot histogram of the data using 5 bins with midpoints (125, 130, 135, 140, 145).
(g) Box plot of the data. Do we have outliers?
