assume that we want to construct a confidence interval. Do one
of the following, as appropriate: (a) find the critical
value
tĪ±/2,
(b) find the critical value
zĪ±/2,
or (c) state that neither the normal distribution nor the
t distribution applies.
Here are summary statistics for randomly selected weights of
newborn girls:
n=278,
x=29.8
hg,
s=6.2
hg. The confidence level is
90%.
Select the correct choice below and, if necessary,
fill in the answer box to complete your choice.