Sorting a tab delimited file

I have a data with the following format:

foo<tab>1.00<space>1.33<space>2.00<tab>3

Now I tried to sort the file based on the last field decreasingly.
I tried the following commands but it wasn’t sorted as we expected.

$ sort -k3nr file.txt  # apparently this sort by space as delimiter

$ sort -t"\t" -k3nr file.txt
  sort: multi-character tab `\\t'

$ sort -t "`/bin/echo '\t'`" -k3,3nr file.txt
  sort: multi-character tab `\\t'

What’s the right way to do it?

Here is the sample data.