**Introduction:**

**In the last section we have come to know about the concept of estimation and the method of Point Estimation to estimate the population parameter. However there is another method of estimation and it is known as “Interval Estimation”. In interval estimation we estimate a interval for the population parameter with a lower boundary and an upper boundary. This interval is known as the confidence interval and the lower boundary is known as the lower confidence limit while the upper boundary is known as the upper confidence limit.**