Ten samples were taken from a plating bath used in an electronics manufacturing process, and the bath pH was determined. The sample pH values are 7.91, 7.85, 6.82, 8.01, 7.46, 6.95, 7.05, 7.35, 7.25, and 7.42. Manufacturing engineering believes that pH has a median value of 7.0.

(a) Do the sample data indicate that this statement is correct?

Use the sign test with   0.05 to investigate this hypothesis. Find the P-value for this test.

(b) Use the normal approximation for the sign test to test versus . What is the P-value for this test?