One group of accounting students used simulation programs, while another group received a tutorial. Scores on an exam were compared.

Statistic Simulation Tutorial

Mean score x1= 9.0 x2=10.8

Sample std. dev s1=2.0 s2=2.1

Number of students n1=30 n2=30

a.Construct a 99 percent confidence interval for the true difference in mean scores.(Round your answers to 2 decimal places. Negative values should be indicated by a minus sign.)

The 99% confidence interval is from___to____.