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%