Compute the critical value z a/2 that corresponds to a 93% level of confidence

Step 1: Calculate the 0.035 that you already know how to do.
Step 2: Calculate 1-0.035 = 0.965
Step 3: Look at the Z table and find 0.965 (or as close to this value as possible)
Step 4: Look at the far left of the row containing 0.965  1.8
Step 5: Look at the top of the column containing 0.965  0.01
Step 6: Add these two values  1.81

Step 6 is your z value that corresponds to that level of confidence.