<h2><em>a) </em><u>The z-value associated with 25.0</u></h2><h2>Z = 1.25</h2><h2 /><h2><em>b)</em> <u>proportion of the population is between 20.0 and 25.0 is</u></h2><h2>Proportion = 0.3944</h2><h2 /><h2><em>c)</em> <u>proportion of the population is less than 18.0 is</u></h2><h2>Proportion = 0.3085</h2>