According to the local union president,the average income of plumbers in the Los Angeles area is $45,000 with a standard deviation of $5,000. A recent investigative report conducted a survey using a simple random sample of 120 plumbers. She found that the average income was $45,520. Is it reasonable to conclude that the plumbers' income is different from $45,000? Test the hypothesis.

H₀: average income

H₁: average income

SE_avg =

z =

p-value =

Conclusion: [ Select ] ["Reject the null hypothesis at the 5% level",

"Fail to reject the null",

"Reject the null hypothesis at the 1% level",

"Reject the null hypothesis at the 10% level"]