In: Statistics and Probability
The body temperatures of a group of healthy adults have a bell-shaped distribution with a mean of
98.13 degrees°F
and a standard deviation of
0.53 degrees°F.
Using the empirical rule, find each approximate percentage below.
| 
 a.  | 
What is the approximate percentage of healthy adults with body
temperatures within 3 standard deviations of the mean, or between
 96.54 degrees°F and 99.72 degrees°F?  | 
| 
 b.  | 
What is the approximate percentage of healthy adults with body
temperatures between
 97.07 degrees°F and 99.19 degrees°F?  | 
Solution :
Given that ,
mean = 
 =98.13
standard deviation = 
 = 0.53
(A)
P(
- 3
<
X < 
 + 2
)
= 99.7%
answer=99.7%
(B)
P(97.07 < x <99.19 ) = P[(97.07 - 98.13) /0.53 < (x -
 ) / 
< (99.19 - 98.13 ) /0.53 )]
= P( -2< Z < 2)
= P(Z <2)+P(Z <-2 )
using empirical rule
=95%/2 + 95%/2
=47.5%+47.5%
=95%
answer=95%