Answer:
0.7207
Explanation:
Mean μ = 84g
SD σ = 1.85g
Upper specification limit (USL) = 88g
Lower specification limit (LSL) = 78g
Cpk = Min[USL - μ/3σ, μ-LSL/3σ]
Cpk = Min[88 - 84/3*1.85, 84-78/3*1.85]
Cpk = Min[4/5.55, 6/5.55]
Cpk = Min[0.7207, 1.0811]
Cpk = 0.7207
So, the process capability index for the current manufacturing process is 0.7207