Caroline manages a team of six salespeople. It's a hard job, one filled with rejection; each person averages $500 in sales per day with a population standard deviation of $100. Caroline heard at a conference that if her employees started doing yoga in the morning, it would improve their mood and thus their sales performance. Caroline tries this; her six people started doing yoga in the morning. The day they started doing this, the average sales for those six employees was $550 per day. What is Caroline's conclusion as a result of this test of improvement