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    Ok, here is the data:

    conditions Observable Number
    Dark,Light 7, 12, 7, 5, 6, 4, 5, 5, = 51
    Dark,Dry 18, 37, 18, 31, 33, 16, 17, 16, =186
    Wet,Light 4, 4, 7, 9, 4, 6, 4, 8, = 46
    Wet,Dark 31, 7, 26, 15, 17, 30, 32, 19, = 177

    Ok, the null hypothesis is that the conditions do not affect the observable number of woodlice seen in each environment

    so expected numbers is the total divided by 4 = 115

    can someone calculate chi squared and tell me what they got so i can compare?

    WHAT IS THE DEGREE OF FREEDOM??
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    degree of freedom is v=m-1xn-1
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    do you have a level of significance? for the question
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    (Original post by samzurai)
    degree of freedom is v=m-1xn-1
    is it 18?
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    (Original post by samzurai)
    do you have a level of significance? for the question
    can you tell me what that is?
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    (Original post by smetin92)
    is it 18?
    no its 1
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    (Original post by smetin92)
    can you tell me what that is?
    the perecentage of error?
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    If you're doing A level biology, then I believe the degree of freedom is 3. No. of groups(in this case 4) - 1 = 3
    and you look at the stats table.
    null hypothesis is that there's no difference between expected and observed data and that any difference is due to chance - insignificant.
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    CHI Squared = sum of (O-E)^2 divided by sum of (E)
 
 
 
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