B.1. Control Charts (15 points)

The dietitian at Aventura Hospital has warned that the meals delivered to patients contain too much sodium. For the past 10 days, she has sampled four batches of the entre du jour and recorded the sodium content per serving. Assume based on historical data that the average sodium content is 500 mg/serving, and the standard deviation is 25 mg.

Day	Sodium Content (mg/serving) Batch 1	Batch 2	Batch 3	Batch 4
1	502	485	516	550
2	495	519	514	480
3	482	516	530	495
4	543	496	402	516
5	475	489	526	502
6	513	489	497	526
7	532	462	523	495
8	495	485	521	505
9	512	523	452	476
10	500	502	513	487

a) Is the process in control? Why or Why not?

b) Given the fact that the sodium content should be between 450 and 520 mg per serving for meal-type products, does the dietitian have a valid concern?