In an office, the distribution of work hours is as shown in the following table.Consider the following inferences drawn from the table : I. The average number of hours worked by a staff member is about 30. II. The percentage of those who worked 35 or more hours is less than 25. III. At least 5 staff members worked more than 44 hours. Which of these inferences is/are valid

In an office, the distribution of work hours is as shown in the following table.Consider the following inferences drawn from the table : I. The average number of hours worked by a staff member is about 30. II. The percentage of those who worked 35 or more hours is less than 25. III. At least 5 staff members worked more than 44 hours. Which of these inferences is/are valid ?