Remark
Two remarks.
1. The weight of the ostrich is on the numerator of the ratio.
2. You have to change units of one of them to make the units the same.
Step One
Change the 150 kg to grams
150 kg * 1000 gram/1 kg = 150,000 grams
Step Two
Find the % of ostrich to hummingbird
Percent = (150,000 / 2) * 100%
Percent = 75000 * 100% = 7 500 000% larger.