For the course of the year we have a number of customers and an average number of days on the WL. We generate this 4 times a year. The number of customers varies from quarter to quarter. We want to generate an average for the entire year.

I know you do not simply add up the number of days on the WL in the 4 quarters and divide by 4 because you have a different number of customers in each quarter. But I can not for the life of me remember how to do this.

This is how many we have for the 4 quarters.

customers 55 days 71

215 days 98

293 days 133

557 days 332