For a sample of 30 employees in one large firm, the mean hourly wage is = $9.50 with = $1.00. In a second large firm, the mean hourly wage for a sample of 40 employees is = $9.05 with = $1.20. Test the hypothesis that there is no difference between the average wage rate being earned in the two firms, using the 5 percent level of significance and assuming that the variances of the two populations are not necessarily equal.