load line analysis pls help

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[/attachment]Hi All,

Currently we had a quiz for load line analysis,
the question was:

Determine the value of R for the circuit below that will result in the diode current of 10mA if E=7V. use approximate analysis method and graph.

I answered Idq=10mA, Id=11.25mA, and R=622ohms because of the statement in the problem as "result in the diode current" i assumed that idq is the current given.

then my instructor says that the answer (Idq)should be should be 9.1mA.

I am very confused because prior examination i found the same question at Electronic devices and circuit theory but in the book the term "use approximation method" was not mentioned.

I attached the capture of the question.

Am i right with my answer? what is the difference with approximation method?

pls help I dont know if I will defend my answer to my instructor.