Answer:
H₀ is accepted, we don´t have evidence to claim valves produces more than 4,1 pounds/square inch
Step-by-step explanation:
Normal Distribution
Population mean μ₀ = 4.1
Population standard deviation σ = 0,9
Sample size n = 260
Sample mean μ = 4,2
Level of significance 0,02 α = 0,02 form z-table we find z score
z(c) = 2,05 (critical value)
Test hypothesis
Null hypothesis H₀ μ = μ₀
Alternative hypothesis Hₐ μ > μ₀
Is a one tail-test ( to the right. Values have a mean over the population mean)
z(s) = ( μ - μ₀ )/ σ /√n
z(s) = 4,2 - 4,1 / 0,9/√260
z(s) = 0,1 *16,1245 / 0,9
z(s) = 1,7916
To compare z(s) and z(c)
z(s) < z(c)
Then z(s) is in the acceptance region, we accept H₀
