An arithmetic sequence arranged from small to large, if the first item of the sequence is divided by 2 and the last item is multiplied by 2, the average of these numbers will increase by 7; if the first item is multiplied by 2, the last item is divided by 2 , the average is less than 2. Knowing that the sum of all the numbers in this arithmetic sequence is equal to 245, find the last term of this sequence.
一个从小到大排列的等差数列，如果把这个数列的首项除以2，末项乘以2，这些数的平均数就增加了7；如果把首项乘以2，末项除以2，平均数就少了2．已知这个等差数列中所有数的和等于245，求这个数列的末项．
<result>56</result>