Final answer:
The percent uncertainty of the bag's weight is approximately 5.88%, and the total weight of fruit bought by Josh at the farmer's market is 1800 grams.
Step-by-step explanation:
The student asks about calculating the percent uncertainty of a bag of apples given a set of weights and their average. To find the percent uncertainty, we generally take the absolute uncertainty and divide it by the mean value, then multiply by 100 to get the percentage. If a 5-lb bag of apples has an average weight of 5.1 lb with an absolute uncertainty of ± 0.3 lb, then the percent uncertainty can be calculated by (0.3 lb / 5.1 lb) × 100%, which results in approximately 5.88%. Hence, the percent uncertainty is 5.88%, which is about 6% when rounded.
For the second question, to find the total weight of fruit Josh bought at the farmer's market in grams, we convert all quantities to grams: 1.5 kilograms of oranges is 1500 grams, 150 grams of grapes remain the same, and 15,000 centigrams of apples convert to 150 grams. Summing these up gives 1500 + 150 + 150 = 1800 grams of fruit.