You were on the right track. Here are two ways to go about it.
• By definition of conditional probability,
Pr[A | B] = Pr[A and B] / Pr[B]
Out of the total 100 participants in the survey, there are 18 people that both have a positive attitude and are over 35, so
Pr[positive and over 35] = 18/100
Out of the 100 pariticipants, 40 are over 35, so
Pr[over 35] = 40/100
Then the conditional probability you want is (18/100) / (40/100) = 18/40 = 9/20.
• There are 40 people over 35 in the survey. You want the probability that someone randomly chosen from this group has a positive attitude, of which there are 18. Hence the probability is 18/40 = 9/20.
To solve for x in terms of b, simply treat b as a number, and solve for x as usual: first of all, we expand the left hand side:
Subtract 10 from both sides:
Divide both sides by -2b:
This means that in particular, if we set 
, we have
Answer:
30,277cm, 629,000mm, 28dm, 1.2km
Step-by-step explanation:
Answer: Approximately 13 ft
Step-by-step explanation: For this, you have to do the Pythagorean Theorem. First set up an equation. That equation is a squared+b squared=c squared. Next, plug in values. A=12 and b=4. The equation becomes 12 squared+4 squared=c squared. Do the math and you'll get 144+16=c squared. Add and get 160=c squared. Then do the square root of both sides and you'll get 12.649=c. Round to nearest whole number to get approximately 13 ft. You can also represent it as the square root symbol with 160 inside, like this(√160).
X = y2 is the equation for it just plug in the numbers
