Question

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

Answer 1

Answer:

There is no sufficient evidence to support the claim.

Step-by-step explanation:

Given the data:

7.91, 7.85, 6.82, 8.01, 7.46, 6.95, 7.05, 7.35, 7.25, 7.42

Sample size, n = 10

The sample mean, xbar = ΣX/ n = 74.07 / 10 = 7.407

The sample standard deviation, s = 0.41158 ( from calculator)

The hypothesis :

H0 : μ = 7

H0 : μ ≠ 7

The test statistic :

(xbar - μ) ÷ (s/√(n))

(7.047 - 7) ÷ (0.41158/√(10))

0.047 / 0.1301530

Test statistic = 0.361

Testing the hypothesis at α = 0.05

The Pvalue ;

df = n - 1 ; 10 - 1 = 9

Two tailed test

Pvalue(0.361, 9) = 0.7263

Since the Pvalue > α ; we fail to reject the Null and conclude that there isn't sufficient evidence to support the claim.