The formula for calculating z score is expressed as
z = (x - μ)/s
where
x is the sample mean
μ is the mean
s is the sample standard deviation
Considering the newborn males,
x = 1700
μ = 3242.4
s = 844.4
Thus,
z = (1700 - 3242.4)/844.4
z = - 1.83
Considering the newborn females,
x = 1700
μ = 3095.9
s = 508.6
Thus,
z = (1700 - 3095.9)/508.6
z = - 2.74
The most extreme value is the z score that is furthest from zero. It is z = - 2.74. Thus, the female who weighs 1700 g is more extreme relatively
Since the z score for the male is z = - 1.83 and the z score for the female is z = - 2.74, the female has the weight that is more extreme.