Calculate the Altman Z-score

Explain in one or 2 sentences per variable why Altman believes each variable is sufficient to measure credit risk (i.e. an analyst can make as informed a decision based on these variables as by adding evn more such as adding more variables such as Average Collection Period and Inventory Turnover.

IV. Assume the following 20 Accts Payable Cash 30 A/R 90 Notes Payable 90 90 Accruals 30 Inventory PP&E 500 Long-Term Debt 150 Retained Earnings Total Equity 400 Total Total Debt and 700 Equity Assets 700 a. Calculate the Altman Z-score b. Explain in one or 2 sentences per variable why Altman believes each variable is sufficient to measure credit risk (i.e. an analyst can make as informed a decision based on these variables as by adding evn more such as adding more variables such as Average Collection Period and Inventory Turnover