can´t get scaling to work properly I'm trying to create a lightbulb using a tutorial on youtube, and I am completely new to Blender.

I'm trying to tighten the bottom of the lightbulb by scaling it down, but it doesn't scale proportionally. Instead it wavers off to the side.

What I have so far:



Expected result (screenshot from the tutorial):
Click this icon and select Median point. 

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