A student measuring the diameter of a pencil of circular cross-section with the help of a vernier scale records the following four readings 5.50 mm, 5.55 mm. 5.34 mm; 5.65 mm. The average of these four readings is 5.5375 mm and the standard deviation of the data is 0.07395 mm. The average diameter of the pencil should therefore be recorded as :

(1) (5.54 ± 0.07) mm

(2) (5.538 ± 0.074) mm

(3) (5.5375 ± 0.0740) mm

(4) (5.5375 ± 0.0739) mm