This exercise relates to the use of Z-Score to determine the significance of the sample mean difference from a given statistic.
Z-Score is defined as the mathematical measure that enumerates the relationship between the value and the mathematical mean of a group of values. It is measured in terms of standard deviations from the mean.
The Z-Score of a measurement x  is mathematically annotated as:
(x - μ)/ δ
x - μ  = 1.74 and δ= 0.69
Hence
Z = 1.74/0.69
= 2.52173913043
approxmately = 2.52
Because Z-Score is greater than 2, hence the sample's mean difference is significant.
Learn more about Z-Score at:
https://brainly.com/question/25638875