Question 1129223
Ho: mean income is <=50000
Ha: mean income is >50000
alpha is 0.05, critical value is 1.645
z=(x bar- mean)/sigma/sqrt(n) (I would use t here, although difference would not be great)
=10000/(10000/sqrt(10))
=10000*sqrt(10)/10000=3.16. This is the Z value,  Sample mean is $60,000
One would reject Ho at the 0.05 level.  p-value is 0.0008
conclude the mean income in Wilmington is > $50000.