Which of the following is a correct statement about uses of PERT and Gantt chart: Group of answer choices PERT and Gantt are useful for planning only when you have historical data on sales. None of them is true for PERT and Gantt. PERT and Gantt are useful for environmental scanning and competitor intelligence. PERT and Gantt are used primarily for project planning and scheduling. PERT and Gantt are qualitative techniques for planning