X673 beats per minute s151 beats per minute use these

x=67.3
beats per minute,
s=15.1
beats per minute
Use these values to calculate the coefficient of variation for the male pulse rates. Round the result to one
decimal place.
CV = sx•100
= 15.167.3•100
= 22.4%
Now, find the coefficient of variation for the female pulse rates. While the mean and standard deviation
can be calculated using either the formulas or technology, for this problem, use technology. Find the
mean and standard deviation for the female pulse rates, rounding the results to one decimal place.
x=78.1
beats per minute,
s=5.8
beats per minute
Use these values to calculate the coefficient of variation for the female pulse rates. Round the result to
one decimal place.

CV = sx•100
= 5.878.1•100
= 7.4%
Therefore, the coefficient of variation for the male pulse rates is
22.4%,
and the coefficient for the female pulse rates is
7.4%.
Use these coefficients to determine whether the variation in the data sets is significantly different.
cm. Use this information to determine whether the adult male foot length of

22.5
cm is significantly low or significantly high.
To use the given formula, first find the midpoint of each class.
Interval 40-49 50-59 60-69 70-79 80-89 90-99 100-109
x=class
midpoint
44.5 54.5 64.5 74.5 84.5 94.5 104.5
Now find n.
n =97
The values of f and x are given in the table below.
Interval 40-49 50-59 60-69 70-79 80-89 90-99 100-109
Frequency 1 1 3 1 16 37 38
x=class
midpoint
44.5 54.5 64.5 74.5 84.5 94.5 104.5
It will be helpful to solve this in parts. First, find
∑
f•x
2
.
∑
f•x
2
=
f
1
•x
1
2
+f
2
•x
2
2
+f
3
•x
3
2
+•••+f
7
•x
7
2
=
1•44.5
2
+1•54.5
2
+3•64.5
2
+•••+38•104.5
2
= 882,614.25
Next, find
∑
(f•x)
2
.
∑
(f•x)
2
=
f
1
•x
1
+f
2
•x
2
+f
3
•x
3
+•••+f
7
•x
7
2
=
[(1•44.5)+(1•54.5)+(3•64.5)+•••+(38•104.5)]
2
= 84,391,782
Now solve for the standard deviation, rounding to one decimal place.
s = n
∑
f•x
2
−
∑
(f•x)
2
n(n−1)
= 97•[882,614.25]−84,391,78297(97−1)
= 11.5
Consider a difference of 20% between two values of a standard deviation to be significant.
The ratio of the computed value to the given value is
1.036 :1.
This corresponds to a
3.6 %
difference. Thus, the computed value is not significantly different from the given value.
a. The empirical rule states that for data sets having a distribution that is approximately bell-shaped, the
following properties apply.
About 68% of all values fall within 1 standard deviation of the mean.