From a sample of 120 batteries, 3 are faulty. Work out the percentage of faulty
batteries.

2.5%

Step-by-step explanation:

% = (faulty batteries / total batteries) x 100

= (3/120) x 100

= 0.025 x 100

= 2.5

the revenue of the fitness center, y, is the product of two factors: the number of members and the fee paid by each member. there are 320 members now, but number of members goes down by 10 for each $5 increase in fees, so if x is the number of $5 price increases then members is equal to (320 - 10x). since the fee is currently $45, and the fee increases by $5 for every price bump x, the fee is given by (45 + 5x). so, revenue y is given by y = (320 - 10x)(45 + 5x).