The vertex of the parabola is between the shortest line connecting its focus and directrix, so between (0, -4) and y = 4 is the point (0, 0), which is the vertex of the parabola. Also, this parabola faces downward.
The general formula for a parabola that faces downward is y = -4cx^2, where c is the distance from the vertex to either to focus or the parabola. Since c = 4, the equation is y = -16x^2, which is choice A.
The total of all angles of a heptagon is 900.
Therefore
x+125+119+117+145+133+140 = 900
x+779 =900
x= 900-779
x =121 degrees
For this Q:
mean=31
st.dev.=0.8
x=32
Calculate z-score:
z=(x-m)/s = (32-31)/0.8=1.25
This z-score value corresponding to the probability of 0.8944
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Answer:
Step-by-step explanation:
