3. The average assembly time for a Ford Taurus is normally

distributed with μ=38 hours ∧σ =1.2 hours. A modification to the

assembly procedure has been made. A random sample of 47

new Ford Taurus automobiles showed the average assembly

time with the new method to be x=37.5 hours. Does this indicate

that the assembly time has been significantly reduced? (Use

a .05 significance level)