Seitzs list of several hundred business to business customerscontinues to grow. Managers would like to know whether the averagedollar amount of sales per transaction per customer has changedfrom last year to this year. Suppose company accountants sampled 20customers randomly from last years records and determined that themean sale per customer was $2300 with a standard deviation of$500. They sampled 25 customers randomly from this years files anddetermined that the mean sales per customer for this sample was$2450 with a standard deviation of $540.