I need some assitance with forming the decision tree!!!!

The senior executives of an oil company are trying to decide whether to drill for oil in a particular field in the Gulf of Mexico. It costs the company $$300,000$ to drill in the selected field. Company executives believe that if oil is found in this field its estimated value will be $$1,800,000.$ At present, this oil company believes that there is a $48\%$ chance that the selected field actually contains oil. Before drilling, the company can hire a geologist at a cost of $$30,000$ to prepare a report that contains a recommendation regarding drilling in the selected field. There is a $55\%$ chance that the geologist will issue a favorable recommendation and a $45\%$ chance that the geologist will issue an unfavorable recommendation. Given a favorable recommendation from the geologist, there is a $75\%$ chance that the field actually contains oil. Given an unfavorable recommendation from geologist, there is a $15\%$ chance that the field actually contains oil.

Assuming that this oil company wishes to maximize its expected net earnings, determine its optimal strategy through the use of a decision tree.