If = 23 ounces, σ = 0.4 ounces, and n = 16, the ±3σ control limits will be
A) 21.8 to 24.2 ounces
B) 23 ounces
C) 22.70 to 23.30 ounces
D) 22.25 to 23.75 ounces
E) none of the above

Question

If  = 23 ounces, σ = 0.4 ounces, and n = 16, the ±3σ control limits will be
A) 21.8 to 24.2 ounces 
B) 23 ounces 
C) 22.70 to 23.30 ounces 
D) 22.25 to 23.75 ounces 
E) none of the above

Quizplus · Accepted Answer

The ±3σ control limits are given by mean ± 3σ/√n. Substituting the given values, we get the control limits as 23 ± 3(0.4)/√16, which simplifies to 23 ± 0.3. Therefore, the control limits are 22.70 to 23.30 ounces, which is closest to option C.

If = 23 Ounces, σ = 0