On 22 April your 0344 zone time DR position is LAT 21°16.0' N, LONG 107°32.0' W. At that time, you observe Spica bearing 236°psc. The chronometer reads 10h 45m 16s, and the chronometer error is 00m 25s fast. The variation is 7.5°E. What is the deviation of the standard compass?

Correct Answer: Option B — 5.2°E

Sight reduction calculations for Spica provide true azimuth based on DR position and time. Comparing the calculated true bearing with the standard compass bearing, then applying chart variation, isolates the local magnetic deviation resulting in 5.2°E.