Answer:
The margin of error for the 94% confidence interval is 0.6154.
Step-by-step explanation:
The (1 - <em>α</em>)% confidence interval for population mean is:
The margin of error of this interval is:
The critical value of <em>z</em> for 94% confidence level is, <em>z</em> = 1.88.
Compute the margin of error for the 94% confidence interval as follows:
Thus, the margin of error for the 94% confidence interval is 0.6154.
Answer:
2nd point
Step-by-step explanation:
Since we are not given any information about the proportion, we will assume the sample proportion to be 0.50
so,
p = 0.50
The Error is 10% percentage point. This means that on either side of the population proportion the error is 5% so E = 0.05
z = 1.645 (Z value for 90% confidence interval)
The margin of error for population proportion is calculated as:
This means 271 students should be included in the sample
One way to do it is with calculus. The distance between any point
on the line to the origin is given by
Now, both
and
attain their respective extrema at the same critical points, so we can work with the latter and apply the derivative test to that.
Solving for
, you find a critical point of
.
Next, check the concavity of the squared distance to verify that a minimum occurs at this value. If the second derivative is positive, then the critical point is the site of a minimum.
You have
so indeed, a minimum occurs at
.
The minimum distance is then
For this case we have the following equation:
The variables are:
t: time in hours
d (t): distance traveled in miles.
We evaluate the distance traveled after 4 hours.
So we have that for t = 4:
Answer:
d (4) = 68
This means that after 4 hours Joanna cycled for 68 miles total
