Calculate Percentage: Finding 46 Silkworms' Two-Day Production Rate of 500-Thread Goal

To solve this problem, we'll follow these steps:

• Step 1: Calculate the total threads produced after two days.
• Step 2: Determine the percentage of Andrea's goal attained using the given goal of 500 threads.

Now, let's work through each step:

Step 1: Calculate threads per day and total threads.
Each worm can produce one thread per day. Andrea has 46 worms. Thus, in one day, the total number of threads produced is:
$46 \text{ worms} \times 1 \text{ thread per worm per day} = 46 \text{ threads}$.

In two days, the total production will be:
$46 \text{ threads/day} \times 2 \text{ days} = 92 \text{ threads}$.

Step 2: Determine percentage of goal achieved.
Andrea's goal is to produce 500 threads. The percentage of the goal reached after two days is:
$\left( \frac{92 \text{ threads}}{500 \text{ threads}} \right) \times 100\%$.

Let's perform the calculation:
$\left( \frac{92}{500} \right) \times 100\% = 18.4\%$, which can be rounded to approximately $19\%$.

Therefore, after two days, Andrea will have achieved approximately 19% of her goal.