4b. Write a C++ program named calcGrades.cpp based on the design you created in Exercise 4a. Step through the code by hand The following is a copy of the file gradeBook.txt found in the Chapo9 folder of your Student Data Files. George Smith 589308 100 90 80 95 85 99 98 97 89 100 90 95 85 85 Elaine Sanders 455436 85 90 80 95 89 99 100 98 97 100 96 98 84 90 Jack Cunningham 235412 72 78 97 84 83 68 85 84 83 9070 75 80 75 Susie Brown 902568 68 85 84 83 90 80 95 85 99 98 75 92 85 87 Marvella Garcia 345432 92 78 97 98 97 89 80 95 85 99 98 89 88 95 Tony Reterson 256436 85 84 83 90 72 78 97 98 97 99 88 87 88 88 John Jones 165435 75 75 80 80 90 90 75 70 87 84 78 82 84 75 Mary Evans 879778 60 89 86 65 89 88 77 60 87 65 65 69 66 60 Nancy Drew 234234 80 75 50 60 79 89 50 45 70 50 60 58 65 45 Lola Zapeta 458741 89 98 79 97 90 96 94 100 99 98 83 78 89 88