Final answer:
The z-score associated with an area of 0.7291 is 0.85.
Step-by-step explanation:
The z-score represents the number of standard deviations a given value is from the mean. In this case, we are looking for the z-score associated with an area of 0.7291 or 72.91%. To find this, we can use a z-table.
By locating the area in the z-table, we can find that the closest z-score is 0.85. Therefore, the correct answer is a) 0.85.