On the Existence and Uniqueness of the Maximum Likelihood Estimators of Normal and Lognormal Population Parameters with Grouped Data

Figure 1

Grouped data: 𝜏₁=2, 𝜏₂=2.5, 𝜏₃=3, 𝜏₄=3.5, 𝜏₅=4. Type I left censored data: 𝜏=2.

(a)

(b)