Overview: 3 questions will be solved this time.Among them
           ☆1 mathematical statistics
           ☆2 arithmetic calculations

[1/3 Formula]
    Work: Calculate the value of equation 11108889+22217778+33326667+44435556+55544445+66653334+77762223+88871112+99980001 .
    Question type: Mathematical calculation
    Solution:
          11108889+22217778+33326667+44435556+55544445+66653334+77762223+88871112+99980001
        =33326667+33326667+44435556+55544445+66653334+77762223+88871112+99980001
        =66653334+44435556+55544445+66653334+77762223+88871112+99980001
        =111088890+55544445+66653334+77762223+88871112+99980001
        =166633335+66653334+77762223+88871112+99980001
        =233286669+77762223+88871112+99980001
        =311048892+88871112+99980001
        =399920004+99980001
        =499900005
    Answer:11108889+22217778+33326667+44435556+55544445+66653334+77762223+88871112+99980001=499900005
[2/3 Formula]
    Work: Calculate the value of equation 12.34+23.45+34.56+45.67+56.78+67.89+78.91+89.12+91.23 .
    Question type: Mathematical calculation
    Solution:
          12.34+23.45+34.56+45.67+56.78+67.89+78.91+89.12+91.23
        =35.79+34.56+45.67+56.78+67.89+78.91+89.12+91.23
        =70.35+45.67+56.78+67.89+78.91+89.12+91.23
        =116.02+56.78+67.89+78.91+89.12+91.23
        =172.8+67.89+78.91+89.12+91.23
        =240.69+78.91+89.12+91.23
        =319.6+89.12+91.23
        =408.72+91.23
        =499.95
    Answer:12.34+23.45+34.56+45.67+56.78+67.89+78.91+89.12+91.23=499.95
[ 3/3 data statistics ]
    Work: Please make statistics on the following data: 7,9,9,7,11,7,5,4,3,8,8,5,7,4,1,2,3,0,9,10,5,9,7 。
    Question type: data statistics
        Total data：23
        The sum：140
        Average value：6.08696
        Variance：8.51418
        Standard deviation：2.91791
    *Note: Totally 5 items are counted.

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