x¼ 47 :5mL=kg
s¼ 4 :8mL=kg
SEðxÞ¼
4 : 8
ffiffiffiffiffi
25
p
¼ 0 : 96
From Appendix C we find that thetcoe‰cient with 24 df for use with a 95%
confidence interval is 2.064, leading to a 95% confidence interval for the popu-
lation meanm(this is the population of joggers’ VO 2 uptake) of
47 : 5 Gð 2 : 064 Þð 0 : 96 Þ¼ð 45 : 5 ; 49 : 5 Þ
Example 4.5 In addition to the data in Example 4.4, we have data from a
second sample consisting of 26 nonjoggers which were summarized into these
statistics:
n 2 ¼ 26
x 2 ¼ 37 :5mL=kg
s 2 ¼ 5 :1mL=kg
SEðxÞ¼
5 : 1
ffiffiffiffiffi
26
p
¼ 1 : 0
From Appendix C we find that thetcoe‰cient with 25 df for use with a 95%
confidence interval is 2.060, leading to a 95% confidence interval for the popu-
lation meanm(this is the population of joggers’ VO 2 uptake) of
37 : 5 Gð 2 : 060 Þð 1 : 0 Þ¼ð 35 : 4 ; 39 : 6 Þ
TABLE 4.5
df
tCoe‰cient
(percentile)
5 2.571
10 2.228
15 2.131
20 2.086
24 2.064
!y 1.960
ESTIMATION OF MEANS 157