The first step is to find the probability value corresponding to z = - 0.82 and z = 2.10 from the standard normal distribution table. Looking at the table,
Probability value corresponding to z = - 0.82 = 0.20897
Probability value corresponding to z = 2.10 = 0.98214
The area under the curve is the difference between both probability values. Hence,
area under curve = 0.98214 - 0.20897 = 0.77317