Diego runs 7 miles in 63 minutes. Use the table below to determine how long it would take Diego to run 4 miles at this rate.
2 answers:
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Answer:
And rounded up we have that n=421
Step-by-step explanation:
We know that the sample proportion have the following distribution:
In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 90% of confidence, our significance level would be given by and
. And the critical value would be given by:
The margin of error for the proportion interval is given by this formula:
(a)
And on this case we have that and we are interested in order to find the value of n, if we solve n from equation (a) we got:
(b)
We assume that a prior estimation for p would be since we don't have any other info provided. And replacing into equation (b) the values from part a we got:
And rounded up we have that n=421
Answer:
option 4. The graph has zeroes at x = 15 an x = -15 and it opens upward.
Step-by-step explanation:
we have
This is the equation of a vertical parabola open upward (the leading coefficient is positive)
The vertex represent a minimum
The vertex is the point (0,-225)
The axis of symmetry is x=0 (y-axis)
Find the x-intercepts (values of x when the value of y is equal to zero)
For y=0
square root both sides
therefore
The graph has zeroes at x = 15 an x = -15 and it opens upward.