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Math Help - Power model equation for data given.

  1. #1
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    Power model equation for data given.

    Im doing a workbook thats using logs and power functions. I have two questions that need to be answered that i cant get around because my booklet doesnt explain how to do it. So here goes:

    The data in the table below shows the results of some baby measurements made in their first 12 months. The data can be modelled by a power function of the form y=ax^b.

    Table=

    Time since birth (x months)- 1,2,3,4,6,8,12
    Average head circumference (y cm)- 36.6, 39.3, 41.0, 42.1, 43.7, 45.0, 46.9


    A) Write your power model equation for the data given above.

    B) Use your model to predict the likely head circumference of a baby at 14 months. show all working.



    Please help !
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  2. #2
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    Re: Power model equation for data given.

    what technology are you permitted to use?
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  3. #3
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    Re: Power model equation for data given.

    Excel or a graphing calculator.
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  4. #4
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    Re: Power model equation for data given.

    If your graphing calculator is a TI (83 or 84) , it will do a power regression with your data entered into lists.

    I performed a power regression on my TI-83 using your data and found y = 36.7x^{.099} (rounded a and b).

    This link ... PwrReg Description

    ... shows how.
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