W.i.p and losses

Hello sir, ive been doing a question on process costing which is as follows :

The following data relate for the latest period
Op wip = 300 kg valued as follows , input material $ 1000 and conversion costs $ 200.
Input during period : 8000 kg at a cost of $ 29475
Conversion costs : $ 11977
Output : 7000 kg
Closing wip : 400 kg

Closing wip is complete as to input material and 70 % complete as to conversion costs. Losses are expected to be 10 % of input during the period and they occur at the end of the process. Losses have scrap value of $ 2 per kg.

What is the value of the completed output ( to the nearest $ ) ?

Sir i have watched your lectures. I have understood that
(debit side)
op wip =300kg
Input 8000 kg
Total makes 8300
Total costs on debit = 42652

(credit side)
Goods produced= 7000kg
Normal loss will be then (0.1 * 8000) = 800kg and it will be valued at scrap of 2 $ which makes 1600 $
Closing wip is 400 kg
Balancing figure therefore i got 100 kg for abnormal loss..

This part of valuing the completed output is confusing me because of the losses mixed with closing inv..i dont understand this part. I searched in bpp txt book i saw in exam focus point ” The study Guide states that losses and work in progress in the same process will not be examined”.

Please sir could you clarify this for me..