Please help me solve this

Question

The mean daily production of a herd of cows is assumed to be normally distributed with a mean of 30 liters, and standard deviation of 7.1 liters.

A) What is the probability that daily production is between 18.1 and 35 liters? Do not round until you get your your final answer.

Answer= (Round your answer to 4 decimal places.)

Warning: Do not use the Z Normal Tables...they may not be accurate enough since WAMAP may look for more accuracy than comes from the table.

Answer 1

Manually calculating the z-scores ((observed value - mean value)/standard dev) we have scores -1.67606 and 0.70423. The probabilities of each score are 0.046864 and 0.75935 respectively. Thus the probability that daily production is between these scores is 0.75935 - 0.046864 = 0.712486 = 0.7125 rounded to four decimal places