Cooking oils that are low in both cholesterol and saturated fats are often recommended for people who are trying to lower their blood pressure or to lose weight. Many cooking oils that have no cholesterol still have saturated fat contents of 6% to 18%. Cooking oil made from soybeans has been advertised as containing 15% saturated fats. A dietician thinks that the percentage of saturated fats is greater than 15% and randomly selects 13 bottles of soybean cooking oil for testing.
These bottles contain the following percentages of saturated fats:
15.2 12.4 15.4 13.5 15.9 17.1 16.9 14.3 19.1 18.2 15.5 16.3 20.0
Do the sample data provide sufficient evidence to conclude that the mean percentage of saturated fats in such cooking oil is greater than 15%? Conduct hypothesis test using ?=.01.