Answer: Day 6
Explanation:
Given: Sayuri's Asian Café 's production is usually between 20 and 22 pot stickers per hour.
After buying new machine she tracks production over the course of seven days.
From the given table we can see from day 1 to day 5 the production is between 10 to 22.
But at day 6 the production was 50 and on day 7 the production was 55 which was rapid increase in production.
Thus, on day 6 the machine make a positive impact on production.