The length of a text messaging conversation is normally distributed with a mean of 2 minutes and a standard deviation of 0.5 min
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Answer:
The answer is
Step-by-step explanation:
Remember that a reflexive relation , where
is the power set of
, is one which conteins the ordered pairs of the form
, for
.
So, As the reflexive and transitive closure of (that we will denote by
) is in particular reflexive, we must add to
the elements
A transitive relation is one in which if the pair
and the pair
are in there, then the pair
must be there too.
So, to complete the relation to be reflexive and transitive we must add the pair
(because
are in
), the pair
, and the pair
because we added the pair
.
Therfore we have that .