Answer:
pairs
Step-by-step explanation:
Given
Profit on selling 'x' pairs of shoes is 
Find the derivative of the function to find out the critical points

Thus, for 4 pair of shoes profit is maximize.
First you need to find the percent equivalent to that of the ratio. The ratio is 3:5. From there you would take the 3, and divide it by 5. 3/5=0.6. Apply that to the information that you are given: 8(0.6)=4.8.
We have:
Event A ⇒ P(A) = 0.16
Event B ⇒ P(B) = 0.09
Probability of event B given event A happening, P(B|A) = P(A∩B) / P(A) = 0.12
By the conditional probability, the probability of event A and event B happens together is given by:
P(B|A) = P(A∩B) ÷ P(A)
P(B|A) = P(A∩B) ÷ 0.16
0.12 = P(A∩B) ÷ 0.16
P(A∩B) = 0.12 × 0.16
P(A∩B) = 0.0192
When two events are independent, P(A) × P(B) = P(A∩B) so if P(A∩B) = 0.0192, then P(B) will be 0.0192 ÷ 0.16 = 0.12 (which take us back to P(B|A))
Since P(B|A) does not equal to P(B), event A and event B are not independent.
Answer: <span>Events A and B are not independent because P(B|A) ≠ P(B)</span>
18/10
9/5
Anything along those lines!