The average height of 60 girls was calculated to be 300 cm. It was detected later that one value of 330 cm was wrongly copied as 270 cm for the computation of the mean. Find the correct mean. A) 301cm B) 300.5cm C) 307cm D) 311cm

1 Answer

Answer :

A)

Calculated average height of 60 girls = 300cm.

Incorrect sum of the heights of 60 girls

= (300 × 60)cm

= 18000 cm.

Correct sum of the heights of 60 girls

= (incorrect sum) - (wrongly copied item) + (actual item)

= (18000 - 270 + 330) cm

= 18060cm.

Correct mean = correct sum/number of girls

= (18060/60) cm

= 301 cm.

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