The easiest way is to try the point (-4,1), that is, x=-4, y=1,
to see which equation works.
b works.
The usual way to do it is to find the equation of the circle
standard form of a circle is (x-h)²+(y-k)²=r², (h,k) are the coordinates of the center, r is the radius.
in this case, the center is (-2,1), so (x+2)²+(y-1)²=r²
the given point (-4,1) is for you to find r: (-4+2)²+(1-1)²=r², r=2
so the equation is (x+2)²+(y-1)²=2²
expand it: x²+4x+4+y²-2y+1=4
x²+y²+4x-2y+1=0, which is answer b.
Answer:
c=50
Step-by-step explanation:
Is this the entire question?
Answer:
20+14
Step-by-step explanation:
Math
Answer:
(1) 97
(2) 385
(3) 9604
Step-by-step explanation:
The (1 - <em>α</em>) % confidence interval for population proportion is:
The margin of error in this interval is:
The formula to compute the sample size is:
(1)
Given:
*Use the <em>z</em>-table for the critical value.
Compute the value of <em>n</em> as follows:
Thus, the minimum sample size required is 97.
(2)
Given:
*Use the <em>z</em>-table for the critical value.
Compute the value of <em>n</em> as follows:
Thus, the minimum sample size required is 385.
(3)
Given:
*Use the <em>z</em>-table for the critical value.
Compute the value of <em>n</em> as follows:
Thus, the minimum sample size required is 9604.