An interior design film would like to have a database to represent its operations. A client (customer) requests that the firm perform a job such as decorating a new home, redecorating rooms, locating and purchasing furniture, and so forth. One of the firm's decorators is placed in charge of each job. For each job, the firm provides an estimate of the amount of time and money required for the entire job. Some of the work for a job, such as planning furniture placement, is done by the decorator in charge of the job. In addition, the firm might hire contractors to work on a daily or hourly basis on a particular job. A job might also include several activities, such as painting, installing floor covering, fabricating draperies, wallpapering, constructing, installing cabinets, and so on. These activities are done by contractors hired by the firm. The contractor provides an estimate for each activity. An activity or job might also require materials such as paint or lumber, and the firm has to keep track of the cost of materials for each activity or job in order to bill the client. The database should store the estimated costs and actual costs of all activities and all jobs. Draw a complete E-R diagram for this example.