Suppose that only 80% of the STUDENT records from Exercise 17.28 have a value for PHONE, 85% for MAJORDEPTCODE, 15% for MINORDEPTCODE, and 90% for DEGREEPROGRAM, and we use a variable-length record file. Each record has a 1-byte field type for each field occurring in the record, plus the 1-byte deletion marker and a 1-byte end-of-record marker. Suppose we use a spanned record organization, where each block has a 5-byte pointer to the next block (this space is not used for record storage).
(a) Calculate the average record length R in bytes.
(b) Calculate the number of blocks needed for the file.