The ratio Jason : Adrian = 1 : 4 means the stickers are divided into 1 + 4 = 5 equal parts.<br><br>
&bull; Jason gets 1 part out of 5<br>
&bull; Adrian gets 4 parts out of 5<br>
&bull; Adrian's share as a fraction of the total = \(\frac{4}{5}\)<br>
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Final Answer: \(\frac{4}{5}\)