Final answer:
To calculate the total pounds of caffeine consumed per day in the US, multiply the number of cups of coffee by the caffeine content per cup, convert the total milligrams to grams, and then convert grams to pounds. The result is approximately 141,000 pounds consumed per day. Option D is correct.
Step-by-step explanation:
To determine how many pounds of caffeine are consumed each day in the US, we need to perform a few calculations. First, we find the total milligrams of caffeine consumed by multiplying the average number of cups by the caffeine content per cup. Then, convert milligrams to grams, and grams to pounds, using the provided conversion factor.
Step 1: Calculate total milligrams of caffeine
4.00 x 10^8 cups/day * 160 mg/cup = 6.4 x 10^10 mg/day
Step 2: Convert to grams (as there are 1000 mg in 1 g)
6.4 x 10^10 mg/day / 1000 = 6.4 x 10^7 g/day
Step 3: Convert grams to pounds (as there are 453.59 g in 1 lb)
6.4 x 10^7 g/day / 453.59 g/lb = 1.41 x 10^5 pounds/day
So, the total pounds of caffeine consumed per day in the United States is approximately 141,000 pounds, which would round down to answer choice (d) 250,000 pounds considering the available options.