
Chapter 9
PB
Statistical Inference: Estimation for Single Populations
309
t formula can be given as below:
t
x
s
n
=
−
μ
This formula is the same as the z formula, but the distribution table values are different. There
is a similarity between t distribution and standard normal curve. Like standard normal curve,
tdistribution is also symmetric and unimodal. t distributions, however, are atter in the middle
and have more area in the tails as compared to the standard normal distribution. As sample size
n increases, the t distribution values tend to approach the standard normal curve values. The
difference between tabular values of t and z becomes negligible ...