Foreign exchange risk management

Dear sir, Today I was practicing a past exam of year (Sep/Dec 19) question 1. Here I got stuck in one part and I need your kind help in this regard.
This is a long question but I will just mention the area where I am confused. The question states that
“Okan Co, a large listed company located in Yasailand whose currency is the Y$,
manufactures engines and engine parts.”
Then the question mentions that it is importing some components from the UK (currency £).

The expected spot exchange rate between the Y$ and the £, in six months’ time, is expected
to be Y$3.03 per £1. The annual inflation rates are currently 2% in the UK and 4% in
Yasailand. It can be assumed that these inflation rates will not change for the foreseeable
future.

In the solution they have used purchasing power parity theory to find spot rates for the upcoming years like this:

Year 1 2 3 4
PPT multiplier 3.03*(1.04/1.02) 3.09*(1.04/1.02) and so on.

My confusion:

As per ppt formula S1= S0 *(1+hc)/(1+hb)

in the denominator, there should be base currency inflation rate and in numerator there should be foreign currency inflation rate.
Okan in located in Yasailand so this is the base currency and its inflation rate as per formula should be included in denominator.
Here they have done in opposite way.

Have they made a mistake?