A soft drink filling machine, when in perfect adjustment, fills the bottles with 12 ounces of soft drink on average. A random sample of 23 bottles is selected, and the contents are measured. The sample yielded a mean content of 11.80 ounces, with a standard deviation of 0.50 ounces. Assume that the amount of soft drink dispensed is normally distributed. At the 10% level of significance can you conclude that the machine is not in perfect adjustment?