求對數內插法解答過程?

題目好像漏打一個字 :
則 x = "整"數

3.7938
= 1.7938 + 2
= log 62.2 + log 100
= log ( 62.2*100 )
= log 6220

3.7945
= 2.7945 + 1
= log 623 + log 10
= log ( 623*10 )
= log 6230

3.7938 ..... log 6220
3.7940 ..... log x
3.7945 ..... log 6230

由內插法得 :
( 3.7940 - 3.7938 ) / ( 3.7945 - 3.7938 ) = ( x - 6220 ) / ( 6230 - 6220 )
( x - 6220 ) / 10 = 0.0002 / 0.0007 = 2 / 7
7x - 43540 = 20
x = 43560 / 7 ≒ 6222.857 ≒ 6223

Ans: 6223