A time-terminated life testing plan is to be found that will reject lots that have a mean

Question:

A time-terminated life testing plan is to be found that will reject lots that have a mean life of 1400 hours with a probability of 0.05. The rejection number is 7, with a sample size of 35. Determine the plan using Handbook H-108, if the time to failure is exponentially distributed. Items that fail during the test are not replaced.