A mean diameter of a thin brass rod is to be measured by vernier calli

1.	A mean diameter of a thin brass rod is to be measured by vernier callipers. Why is a set of 100 measurements of the diameter expected to yield a more reliable estimate than a set of 5 measurements only?
Answer» Increasing the number of observations, increases the reliability as the mean error is also reduced. The best possible value is. a_mean = (a₁ + a₂ +a₃ +........ +a_n)/n This will give a better value, if n is large.

A mean diameter of a thin brass rod is to be measured by vernier callipers. Why is a set of 100 measurements of the diameter expected to yield a more reliable estimate than a set of 5 measurements only?

Answer»

Increasing the number of observations, increases the reliability as the mean error is also reduced. The best possible value is.

a_mean = (a₁ + a₂ +a₃ +........ +a_n)/n

This will give a better value, if n is large.