The conclusions of these two reports differ enormously.
Tips
usage
相去甚远 is a four-character set phrase used to compare two things abstractly — opinions, results, standards, ideals vs reality. Pattern: A 与/和 B 相去甚远 ('A and B are worlds apart'). Slightly literary; common in editorials and academic writing.
grammar
Parse it as 相去 ('mutual distance') + 甚 ('very') + 远 ('far'). The literary 甚 ('extremely') gives the phrase its formal flavor; the everyday equivalent would be 差得很远 (chà de hěn yuǎn).