A recent national survey found that high school students watched an average (mean) of 6.7 DVDs per month with a population standard deviation of .80. A random sample of 40 college students revealed that the mean number of DVDs watched last month was 6.20. At the .05 significance level, can we conclude that college students watch fewer DVDs a month than high school students?

Compute the value of the test statistic. (Negative amount should be indicated by a minus sign.Round your answer to 2 decimal places.)

Value of the test statistic______________