Question 1041535
False.  I don't like the question, because 30 is somehow considered magical.  
Nevertheless, given the information above, with a normal distribution, people will use a z-test with a sample size greater than 30.  The t-test is reserved for sample sizes less than 30, which is why t-tables are structured the way they are.  At n=30, there is about 4% error; at n=60 about 2% error, and at n=100 about 1% error.