statistics
posted by Badar on .
A department store management claims that families spend an average of $625 on gifts during the Christmas season. A sample of 120 families showed that they spent an average of $665 on gifts during the past Christmas season with a standard deviation of $135. Test at the 10% significance level if the mean amount spent on gifts during the Christmas season by all families is different from $625.

See your previous post for the process.