In a manner that is based on assumption rather than proof.

एक तरीके से जो निष्कर्ष पर आधारित है न कि प्रमाण पर।

English Usage: The decision was made presumptively, assuming all the necessary information was available.

Hindi Usage: निर्णय presumptively लिया गया, यह मानते हुए कि सभी आवश्यक जानकारी उपलब्ध थी।