Answer:
And rounded up we have that n=656
Step-by-step explanation:
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 80% of confidence, our significance level would be given by 
and 
. And the critical value would be given by:
Solution to the problem
The margin of error for the proportion interval is given by this formula:
(a)
Since we don't have prior info for the proportion of interest we can use 
as estimator. 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)
And replacing into equation (b) the values from part a we got:
And rounded up we have that n=656
Answer:
Step-by-step explanation:
To write this equation with h isolated, we cancel everything else on the right hand side of the equals sign. This means we cancel π and r².
Since both of these are attached to h by multiplication, we divide by both to cancel. We can divide by both at the same time:
Answer:
-0.25, -1/5, -2.5, -5, -10
Step-by-step explanation:
Answer:
3x³ - 2x² + 1 = 0
Step-by-step explanation:
By definition, a quadratic equation cannot have an exponent higher than 2.
X + y = 25
x is the smaller number.
y is the smaller number plus 9 (x + 9).
x + (x + 9) = 25
2x + 9 = 25
2x = 16
x = 8
8 + y = 25
y = 17
The numbers are 8 and 17.
