Assume you apply the Mt version of the Capture-Recapture model to the following data collected by two reviewers during the review of a design document:

Defect number  1 2 3 4 5 6 7 8 9

Reviewer 1     x x x x

Reviewer 2         x x x x x x x 

An ‘x’ indicates that a reviewer has found the defect with the corresponding number.

What would be the estimate of the remaining faults, i.e., the number of faults not yet found by any of the reviewers?