K Researchers developed a function that can be used to accurately predict the weight of female cows, W(t) =535 (1 - 0.915 e -0.0019t) 1.2465 , where W(t) is the weight of a cow (in kg) that is t days old. Complete parts (a) through (d) below. . . . a. What is the maximum weight of the average cow? The maximum weight of the average cow is 535 kg. b. At what age does a cow reach 85% of this maximum weight? A cow reaches 85% of this maximum weight when it is about 1059 days old. (Do not round until the final answer. Then round to the nearest integer as needed.) c. Find W'(1000) and interpret. W'(1000) = (Round to two decimal places as needed.)