A paint manufacturer claims that his paint will last on average 5 years. Assuming that lifetime of his paints is normally distributed and has a standard deviation of half a year, answer the below questions.

1. Suppose that you are a contractor and you painted one house with this paint. It lasted for 4.5 years. Would you consider this as evidence against manufacturers claim? Show calculations relevant to your answer.
2. Suppose that you paint 15 houses with his paint. It lasted an average of 4.5 years for the 15 houses. Would you consider that as evidence against the manufacturer's claim? Show calculations relevant to your answer.