Answer:
The significance level of difference in fhe two means is indeed 0.26.
Step-by-step explanation:
To obtain the significance level, just standardize the mean in 2012 with the new mean and standard deviation.
The standardized score (z) is the value (x) minus the mean (xbar) then divided by the standard deviation (σ)
z = (x - xbar)/σ = (49007 - 49800)/3100 = - 0.26
Therefore, the significance level of difference is indeed 0.26.