Hypothesis Testing/P-Value

My last question!

Listed below are the # of homeruns for the National League leader over the last 20 years. Assuming that # of homeruns is normally distributed, if this is sample data collected from a population of all past & future homerun leaders, test the claim that the mean homerun leader has less than 47 homeruns, where α=.05. Set up & complete the appropriate hypothesis test. For this data, also compute the p-value. Finally, compute 85% & 98% Confidence Intervals for this data.

Year (Homerun)

2006 (58)

2005 (51)

2004 (48)

2003 (47)

2002 (49)

2001 (73)

2000 (50)

1999 (65)

1998 (70)

1997 (49)

1996 (47)

1995 (40)

1994 (43)

1993 (46)

1992 (35)

1991 (38)

1990 (40)

1989 (47)

1988 (39)

1987 (49)

(The sum of all the homeruns is 984. The mean is 49.2)

I know this should be a left-tailed test since it states "less than". But I'm very confused about how to set it up. Would I state Ho:u=47 (null) & H1:u<47 (alt)? And where do I go from there (I think I know but I'm not 100% sure).

If anyone can help (or at least point me in the right direction), I'd appreciate it.

Thanks!