The sales department of a beverage company needs to formulate a new year's sales plan. In order to determine the relationship between the advertising expenses x (ten thousand dollars) and the sales volume y (ten thousand dollars), please calculate the sample correlation coefficient according to the following statistical data, and explain the direction and degree of correlation between the advertising expenses and the sales volume.

advertising expenses x	40	25	20	30	40	40	25	20	50	20	50	50
sales volume y	490	395	420	475	385	525	480	400	560	365	510	540