Is this 2-Tail test? Or 1-Tail test? In this case what I use for H0? I know the standard deviation, what number represent The mean in the equation is it 1955? Or 1800?

For the Bank the average savings account balance in year 2008 was $1800. 

 A random sample of 30 savings account balances for the year 2009 yielded a mean of $1955 and a standard deviations of $123.  

At a = 0.05significance level can we conclude that in 2009 the mean savings account balance differs from the mean savings account balance in 2008?

Answer rating: 100% (QA)

To determine whether this is a 1tail or 2tail test lets first establish the hypotheses Null Hypothes... View the full answer