iPhone 4S Battery

Take it in for replacement.

Can't state what is "normal" without knowing what the usage involved.   Was all internet access done when connected to an available wi-fi network, or was some or all internet access done when connected to the cellular network? If any when connected to the cellular network, what was the cellular reception level at the time and were you connected to 3G or EDGE?

The same for calls and SMS/MMS. What was the cellular reception when placing or receiving calls and overall when not using the iPhone?

The lower the cellular reception level or when the level is low, more battery will be used when not using the phone but even more so when using any cellular functions.

Did any of the usage involve processor intensive activity with a game, etc.?

What is your screen brightness? A brighter setting for the screen will use more battery than a lower setting.

There are many factors that affect battery life.

You don't say what the battery level is after this usage.