9(30+7) = (9*30)+(9*7)
This is the distributive property
x(y+z) = xy + xz
Let the dash = x
9(30+7) = (9*x)+(9*7)
9(37) = 9x + 63
333 = 9x + 63
Substract 63 from both sides
333 - 63 = 9x +63-63
270 = 9x
Divide both sides by 9
270/9 = 9x/9
30 = x
Or x = 30
Set Events:
T=tests positive~T=tests negativeP=subject is pregnant~P=subject is not pregnant
We are givenP(T n ~P)=0.02P(~T n P)=0.03P(P)=0.7
recall by definition of conditional probabilityP(A|B)=P(A n B)/P(B)
Need to find P(P|~T)
First step: make a contingency diagram of probabilities (intersection, n)
P ~P sum
T 0.67 0.02 0.69=P(T)
~T 0.03 0.28 0.31=P(~T)
sum 0.70 0.30 1.00
=P(P) =P(~P)
therefore
P(P|~T)=P(P n ~T)/P(~T)=0.03/0.31 [ both read off the contingency table ]
=0.0968
The answer is x=3.6 or 3 3/5.
First we convert the decimal answer to a fraction; 0.9 is read as "nine tenths," so the corresponding fraction is 9/10:
1 5/6 - (x - 7/12) + 2 1/12 = 9/10
Now we find a common denominator. The first thing that 6, 12 and 10 will all divide into is 60:
1 50/60 - (x - 35/60) + 2 5/60 = 54/60
Distributing the negative, we have:
1 50/60 - x + 35/60 + 2 5/60 = 54/60
Combining like terms, we have:
-x + 4 30/60 = 54/60
Subtracting 4 30/60 from each side, we have:
-x + 4 30/60 - 4 30/60 = 54/60 - 4 30/60
-x = -3 36/60
Divide both sides by -1:
-x/-1 = (-3 36/60)/-1
x = 3 36/60 = 3 3/5 = 3.6
Answer:
d
Step-by-step explanation:
