Answer: There are 69 adults and 72 children went to the concert.
Step-by-step explanation:
Let x be the number of adults, and y be the number of children.
x + y = 141
3.5x + 2.5y = 421.5
x + y =141
x = 141 - y
3.5(141 - y) + 2.5y = 421.5
493.5 - 3.5y + 2.5y = 421.5
493.5 - y = 421.5
-y = -72
y = 72
x + y = 141
x + 72 = 141
x = 69
Answer:
1) 0.700
2) 0.730
3) 0.030
4) 0.959
Step-by-step explanation:
1) proportion of support for the ban with at least one child =
= 
= 0.700
2) proportion of support for the ban with no child =
= 
= 
= 0.730
3) Difference in proportion of supporters for the ban between those with atleast one child and those with no child
= 0.700 - 0.730
= -0.03
4) Relative risk = 
=
= 0.959
You can do substitution 2x-2=x^2 -x -6; isolate all terms on one side 0= x^2 -x-2x -6+2; combine like terms x^2 -3x -4=0; factor the quadratic (x-4)(x+1)=0; each term is zero x-4=0 so x=4 and x+1=0 so x=-1. Now, y=2•4-2=6 and y=2•(-1) -2= -4 ; solutions for the system are ( 4,6) and ( -1, -4)
Answer is 280
First, find A = 35% (100% less the three known percents = 35
Second, find ratio of B
20% of x = 160
Divide 160/.20 to isolate x
X=800 (total biscuits)
Now take A percentage x 800 biscuits
800 x 35% = 280 people chose biscuit A