Answer
Confidence interval: $103.656\lt x ̅ \lt112.344$
Work Step by Step
$n=25$, so:
$d.f.=n-1=24$
$level~of~confidence=(1-α).100$%
$96$% $=(1-α).100$%
$0.96=1-α$
$α=0.04$
$t_{\frac{α}{2}}=t_{0.02}=2.172$
(According to Table VI, for d.f. = 24 and area in right tail = 0.02)
$Lower~bound=x ̅ -t_{\frac{α}{2}}.\frac{s}{\sqrt n}=108-2.172\times\frac{10}{\sqrt {25}}=103.656$
$Upper~bound=x ̅ +t_{\frac{α}{2}}.\frac{s}{\sqrt n}=108+2.172\times\frac{10}{\sqrt {25}}=112.344$
