Edit Text String Based on 3rd Occurrence of Char

74.55.245.28
78.46.99.8
78.46.99.8
85.25.120.116
196.7.147.40

I need a formula that delete all characters after the final "."

so above would be e.g. 196.7.147

How do I do a search from right to left? (problem with left to right is that position of final . varies!)

Any help will be appreciated!