A manager needs to have summary sales information by product line available to her on a timely basis when purchasing decisions need to be made. The type of information system most likely to provide this type of information would be classified as a

Management information

Explanation:

From the question we are informed about instance, whereby A manager needs to have summary sales information by product line available to her on a timely basis when purchasing decisions need to be made. In this case, The type of information system most likely to provide this type of information would be classified as a Management information. Management information system can be regarded as a an information system that is been used in decision-making as well as in the coordination, control and analysis or visualization of information in an organization.

Studing of management information systems encompass the people as well as the processes and technology as regards an organizational context.