Download Section 9.2 Extra In-Class Exercises Find the range and standard

Section 9.2 Extra In-Class Exercises
Find the range and standard deviation of the following set of data.
For the standard deviation, round to the nearest tenth.
168, 157, 163, 174, 147, 166, 166
Find the standard deviation of the set of grouped data.
Round answer to the nearest tenth.
COLLEGE UNITS
0–9
10 – 19
20 – 29
30 – 39
40 – 49
50 – 59
FREQUENCY
4
3
6
3
5
9
An assembly-line machine turns out washers with the following
thicknesses (in millimeters). Find the mean and standard deviation of the
thicknesses. Round both answers to four decimal places as needed.
1.69 1.84 1.76 1.94 1.58 2.02 1.27 1.68
1.33 1.92 2.08 1.39 1.53 1.84 1.85 1.95
A medical lab tested 8 samples of human blood for acidity on the pH
scale with the results below. What percentage of the data is within the
given standard deviations of the mean? (Round to the nearest whole
percentage.)
7.5 7.1 7.4 7.3 7.2 7.5 7.4 7.2
(a) ___% of the data is within 1 standard deviation of the mean.
(b) ___% of the data is within 2 standard deviations of the mean.
A medical lab tested 8 samples of human blood for
acidity on the pH scale with the results below.
7.8 7.9 7.1 7.2 7.1 7.6 7.5 7.5
Find the percentage of the data within:
(a) 1 standard deviation of the mean
(b) 2 standard deviations of the mean
(c) 3 standard deviations of the mean
Chebyshev's Theorem states that for any set of
numbers, the fraction that will lie within
k standard deviations of the mean is at least
.1
I
-_
k'
{a} Using this result, find the fraction of all the
numbers of a data set that must lie within
3 standard deviations of the mean.
(b) Find the fraction of all the numbers of
a
data set with a mean of 60 and standard
deviation 4 that must lie between 48 and 72.
(c) Find the fraction of all the numbers of a
data set with a mean of 60 and standard
deviation of 4 that are less than 48 and
greater than 72.