SSHA scores range from 0-200. U.S. college students mean score is 115 with a std dev of about 30

SSHA scores range from 0-200.  U.S. college students mean score is 115 with a std dev of about 30.  A teacher suspects older students have better attitudes and gives 25 students who are 30 years of age or older the test.  Their mean score is x=133.2.  Assuming that o=30 for population of older students carry out a test of Ho: u=115, Ha: u>115.  Report the p-value (which I calculated and came up w/ .0012.  I'm struggling with a sketch to illustrate it.  My conclusion is older students have a higher SSHA mean. So please do a sketch (showing p-value)  and verify if my conclusion is correct.