Digit precision with N command when working with machine precision numbers

Questions
,
1

I have something like this:

N[Mean[{3.81913, 243.354}], 3]

It outputs

123.587

because the mean of that list is a Machine Precision number and then, N[ ] does nothing. How can I force Mathematica to show the number of digits I want in a case like this one?

2

Possibly

N[Mean[Rationalize@{3.81913, 243.354}], 3]

is one way to go… when you are working with machine precision numbers then machine precision arithmetic is used throughout the calculation.

3

SetPrecision[…,3] should do this.

4

Thanks!, both options worked.