Answer: <u><em> B 9.25</em></u>
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Step-by-step explanation:
You have to do a histogram here:
<span>11 sec: 2 people: probability is 2/50 = 1/25 = 0.04
12 sec: 5 people: probability is 5/50 = 1/10 = 0.1
13 sec: 8 people: probability is 8/50 = 4/25 = 0.16
</span>14 sec: 10 people: probability is 10/50 = 1/5 = 0.2
15 sec: 21 people: probability is 21/50 = 2.38
16 sec: 2 people: probability is 2/50 = 1/25 = 0.04
17 sec: 2 people: probability is 2/50 = 1/25 = 0.04
Answer:
centre = (- 3, - 2) , radius = 1
Step-by-step explanation:
The equation of a circle in standard form is
(x - h)² + (y - k)² = r²
where (h, k) are the coordinates of the centre and r is the radius
Given
x² + 6x + y² + 4y + 12 = 0 ( subtract 12 from both sides )
x² + 6x + y² + 4y = - 12
Use the method of completing the square on the x and y terms
add ( half the coefficient of the x/ y terms )² to both sides
x² + 2(3)x + 9 + y² + 2(2)y + 4 = - 12 + 9 + 4
(x + 3)² + (y + 2)² = 1 ← in standard form
with centre = (- (- 3), - (- 2)) and r² = 1, that is
centre = (- 3, - 2) and radius = 1