PHP remove duplicate values from multidimensional array

I'm trying to figure out how to merge duplicate array entries, in a multidimensional array.

Here's an excerpt of my data:

Accounting/Business - 86.02
   1->Demonstrate analytical and critical-thinking skills with direct application to business environments. => 85.71
   2->Communicate ideas and information effectively both orally and in writing. => 90.48
   3->Demonstrate skill in the use of computer software application and technology in business and industry. => 90.48
   4->Demonstrate skill in the use of computer software application and technology in business and industry. => 85.71

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What I'm trying to do is find anywhere that the text is the same, and merge them into a single key=>value pair.  But aside from just merging the text, the numbers need to be added (and averaged) together to create a new number.

Ideally the above snip would become the following snip:

Accounting/Business - 86.02
   1->Demonstrate analytical and critical-thinking skills with direct application to business environments. => 85.71
   2->Communicate ideas and information effectively both orally and in writing. => 90.48
   3->Demonstrate skill in the use of computer software application and technology in business and industry. => 88.095

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The new number (88.095) created by the following = ((90.48+85.71)/2).

Anyone have any ideas?  I have been trying to get this all day, but I can't seem to find any info that helps or figure it out myself...  Thanks for any assistance in this...