The Iowa Department of Transportation repaired hundreds of bridges in 1993. To check the average cost to repair a bridge, a random sample of n = 55 bridges was chosen. The mean and standard deviation...

The Iowa Department of Transportation repaired hundreds of bridges in 1993. To check the average cost to repair a bridge, a random sample ofn = 55 bridges was chosen. The mean and standard deviation for the sample are $25,788 and $1,540, respectively. Records from previous years indicate an average bridge repair cost was $25,003. Use the sample data to test that the 1993 meanμυ is greater than $25,003. Useα = 0.05.


The hypothesis to be tested is:
H0: mu=25003 vs. Ha: mu not equal to 25003
The test statistic is z=3.78


Please state the correct decision?