Z=(175.1-177.9)/2=-1.4. So X is -1.4 standard deviations from the mean. This is equivalent to 1-P(Z=1.4).
P(Z=1.4)=0.9192, so P(Z=-1.4)=1-0.9192=0.0808. This is the probability of X<175.1, so the probability of X>175.1 is 1-0.0808 which brings us back to 0.9192. In other words, there's a 91.92% probability of X being higher than 175.1.