Answer:
(0.4958, 0.7422)
Step-by-step explanation:
Let p be the true proportion of water specimens that contain detectable levels of lead. The point estimate for p is
. The estimated standard deviation is given by
. Because we have a large sample, the 90% confidence interval for p is given by
where
is the value that satisfies that above this and under the standard normal density there is an area of 0.05. So, the confidence interval is
, i.e., (0.4958, 0.7422).
Answer:
Step-by-step explanation:
"<u><em>The size of the tank</em></u> a fish collector needs <u><em>depends</em></u> on <em>how many fish he has</em>."
Dependent variable is the size of the tank.
<em>Independent variable</em> is how many fish a fish collector has.
Answer:
243
Step-by-step explanation:
make 90% into a decimal
0.9
multiply 270 by 0.9 to get the answer of 243