Answer:
Since [tex]|Z| = 2.52 > 2[/tex], the difference is significant.
Step-by-step explanation:
Z-score:
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
If |Z| > 2, the measure X is significent.
In this question:
[tex]|X - \mu = 1.74|, \sigma = 0.69[/tex]
So
[tex]Z = \frac{1.74}{0.69} = 2.52[/tex]
Since [tex]|Z| = 2.52 > 2[/tex], the difference is significant.