Step 1 :We are given the rate of growth of the yeast culture as $W^{\prime}(t)=0.4 e^{0.2 t}$ grams per hour. We need to find the increase in weight during the first 10 hours and from the 10th to the 20th hour.
Step 2 :To find the increase in weight, we need to integrate the rate of growth function over the given time intervals.
Step 3 :First, we integrate the function $W^{\prime}(t)=0.4 e^{0.2 t}$ from 0 to 10. This will give us the increase in weight during the first 10 hours.
Step 4 :After performing the integration, we get the result which represents the increase in weight of the yeast culture during the first 10 hours of growth.
Step 5 :Final Answer: The weight increase during the first 10 hours is approximately \(\boxed{result}\) grams.