Question 1135429
That probability uses z>=(x bar-mean)/sigma/sqrt(n)
z>=(159-168)/34/sqrt(10)
this is z>=-9*sqrt(10)/34, which is z>=-0.84
This has probability 0.7995
One can't say whether or not it is safe; one may say that with high probability, ten normal men would have a mean weight exceeding the maximum capacity.  It would be up to engineers to say with that information whether the elevator itself would be safe.