Question 1106396
z=(x-mean)/sd
z< (65-64.3)/3.1=z < +0.23
that probability is 0.5893

The second one is divided by the standard error, which is 3.1/sqrt(50)
That quotient is 0.438
z < 0.7/0.4380 <1.60
That probability is 0.9450; much less likely to find an average >65.