Answer:
a) Grade = 93, Standard score = 1.5
Grade = 62, Standard score = -1.6
b) Standard scores = 0.6, Grade = 84
Standard scores = 1.2, Grade = 90
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 78
Standard Deviation, σ = 10
Formula:

a) Grade = 93

Grade = 62

b) We have to find grades of student
Standard scores = 0.6

Grade = 84
Standard scores = 1.2

Grade = 90