Final answer:
The cost of a slot on a highly-rated show is 125% more than the average cost for a 30-second commercial. The calculation is based on the increase from $200,000 to $450,000.
Step-by-step explanation:
To calculate the difference in cost between an average time slot and a slot on a highly-rated show for a 30-second commercial, we first determine the increase from the average cost to the cost for the highly-rated show.
The average cost is $200,000, and the highly-rated show costs $450,000.
The difference between these two costs is
$450,000 - $200,000 = $250,000.
Next, to find the percentage increase, we divide the difference by the original amount (average cost) and multiply by 100:
$$\frac{$250,000}{$200,000} \times 100 = 125\%$$
Therefore, the cost for a slot on a highly-rated show is 125% more than the cost of an average time slot. This is reflected in choice a. 125%.