Managers at Matthew's Sporting Goods are concerned that the dumbbells from one of the store's new suppliers are poorly made. To investigate, the managers used a precision scale to weigh a random sample of 50 weights labeled "30 kg." They found that the dumbbells in the sample weighed an average of 30.1 kilograms, with a standard deviation of 3 kilograms. Find a 90% confidence interval for the mean weight of "30 kg" dumbbells manufactured by the new supplier.
Round your answers to the nearest tenth.