Draw a simple ERD diagram for each of the following examples. Include proper cardinality and all keys. Besides PK and FK, include one other attribute. Do these in Astah! Show how to "fix" M:N relationships

1. Political surveys designed by Gant Corporation are developed by only one specific team and are given to many recipients (the number of recipients must be at least twelve times the number of survey items; some surveys are actually developed but not given). Any particular team may develop many surveys or the team may be new and have not yet developed any surveys. A recipient, assigned randomly from the general population, may take no more than one survey.

2. At Clark Hospital, a patient may be admitted to only one ward (if admittance is warranted). Each patient has only one assigned physician, although a physician may have many patients. A ward is attended by at least one (but possibly more) physicians (and physicians may be assigned to multiple wards). Award may have many patients.

3. Scientists at Wade Chemicals may work on one project at a time (the company only keeps track of their current project). Projects are manned by one or more scientists. In order to carry out these projects, scientific instruments may be used in a project. However, a particular instrument may only be assigned to one project to avoid contamination (and then discarded). An instrument may be checked out to more than one scientist working on the project. A scientist may check out more than one instrument. A project manager (who is not a scientist) may be assigned to head one project (managers will never head more than one). A project must have one and only one project manager.