Give a 99.5% confidence interval, for

μ

1

−

μ

2

given the following information.



n

1

=

25

,

¯¯¯¯

x

1

=

2.79

,

s

1

=

0.69



n

2

=

20

,

¯¯¯¯

x

2

=

2.82

,

s

2

=

0.63