Standard Cost Conversion While Making Purchase Orders

Hello,

I have one item and its cost is rupees 251.62/- When I create a foreign Purchase Order in USD, AX is automatically converting the same Item’s “Unit Price” into 4.6. In what basis AX is converting the cost into 4.6 ? Any idea? In fact I checked the exchange rate and found there is no exchange rate at 54.70 i.e. 251.62/4.6

If anyone can help me to explain what logic AX is applying when converting the Item standard cost into foreign currency when making foreign purchase orders.

All Items' cost is stored in Standard Cost and its uploaded under Item costing version.

Thanks in advance.

Regards,

Sajeesh