Answer:
The correct answer is "(18, 30) minutes".
Step-by-step explanation:
Mean,
= 24
Standard deviation,
= 2
The range of minutes where 99.7% of individuals completed the quiz will be:
= 
On substituting the values, we get
= 
= 
now,
= 
= 
Or,
= 
= 
i.e., 18 to 30 minutes
Find the roots
solve
we use hmm, completing the suare
2(x²-1.5x)=4
divide both sides by 2
x²-1.5x=2
take 1/2 of linear coeiftn and square it
-1.5/2=-0.75, (-0.75)²=0.5625
add that to both sides
x²-1.5x+0.5625=2+0.5625
factor perfect squaer trinomial
(x-0.75)²=2.5625
square root both sides, remember to take positive and negative square roots
x-0.75=+/-√2.5625
add 0.75 to both sides
x=0.75+/-√2.5625
the roots are x=0.75+√2.5625 and x=0.75-√2.5625
1/a and 1/b
1/(0.75+√2.5625) and 1/(0.75-√2.5625)
if the roots of a quadratic equation are r1 and r2 then it factors to
(x-r1)(x-r2)
so then we can factor our equation to be

if we were to try and expand it, we would get
x²+0.75x-0.5
that's the simpliest equation with roots 1/a and 1/b where a and b are he roots of 2x²-3x=4
x²+0.75x-0.5 is answer
Answer:
radius= diameter/2= 10/2
*radius=5
circumference= diameter*pi=10*3.14
*circumference=31.4
Step-by-step explanation: hope this helps
Answer:
2.44
Step-by-step explanation:
12 1/2 / 5 =2.44