statistics

A college professor claims that the entering class this year appears to be smarter than entering classes from previous years.  He tests a random sample  of 12 of this year's entering students and finds that their mean IQ score is 115, with standard deviation of 13. The college records indicate that the mean IQ score for entering students from previous years is 112.  If we assume that the IQ scores of this year's entering class are normally distributed, is there  enough evidence to conclude, at the 0.1 level of significance, that   the mean IQ score, μ,  of this year's class is greater than that of previous years? 

 Perform a one-tailed test.       

Carry your intermediate computations to at least three decimal places and round your answers as specified in the table. (If necessary, consult a  list of formulas.)