The <em><u>correct answer</u></em> is:
c)75.4 to 94.6
Explanation:
The formula for a confidence interval is:
,
where μ is the mean, z is the z-score associated with the level of confidence we want, σ is the standard deviation, and n is the sample size.
Our mean is 85, our standard deviation is 12, our sample size is 6, and since we want 95% confidence, our z-score is 1.96:
Answer:
(0.3798, 0.4602)
Step-by-step explanation:
Let p be the true proportion of US adults who believe raising the minimum wage will help the economy. A point estimate for p is and a good aproximation (because we have a large sample) for the standard deviation of
is
. Therefore, a 99% confidence interval for p is given by
where
and
is the
th quantile of the standard normal distribution, so we have,
, i.e.,
or equivalently (0.3798, 0.4602).
A piece of wire is cut into two pieces. That means each part would be assigned an unknown variable. Let one part be x and the other part be y.
That means,
If the longer part is x, and the longer part is 3cm longer than the shorter part, then we would have the following;
We can now refine the equation as follow;
ANSWER:
The length of the shorter piece of wire is 6cm