request to solve a formula to find the weight of pigs at different days of during an experiment

[Ricavita0118]

hello,

i attache the file with the problem i would like to solve:

in a experiment we measured the weight of pigs after weaning.

in the experiment there are 2 groups, group A (normal diet + product A), and group control (normal diet).

we measured the animals at the day0 (entering the experiment) , then at day 7, 14, and 35.

we do not have the weights in the other days of the experiment, and i would like to find the formula that helps me to estimate the weights in those days and fill the table with the empty cells.

thank you so much to whoever is able to help.

thank you.

[#2]

@Ricavita0118 I have taken average growth during the period to take use of to get the estimated weights.

Hope it helps.

[#3]

@AshaKantaSharma thank you for your help.

unfortunately the average seems do not work because if we use the linear trend line does have a R2 very low.

I've tried to use the polynomial equation (degree 2) formula but i'm not able to solve it..

the R2 obtained with the polynomial trend line seems to be closer to the real situation, but i'm not able to solve it.

the equation of one curve is 

y = 2.1482x2 - 6.7453x + 12.323
R² = 0.9793

and the other is 

y = 2.0975x2 - 6.8495x + 12.469
R² = 0.9787

is it the right direction i am following or i am totally wrong?

thanks  a lot

[#4 · Accepted solution]

@Ricavita0118 

If use polynomic approximation we may find coefficients with LINEST() function. For such one

 formula for first curve coeficients is

=LINEST(C4:F4,$C$7:$F$7^{1;2;3},TRUE,FALSE)

If your Excel doesn't support Dynamic Arrays enter it as array formula (Ctrl+Shift+Enter)

[#5]

dear @Sergei Baklan ,

first of all thank you so much for the help and i realy appreciate you work. it is amazing.. wow!

i will try to look for that formula and see if i can learn more about it!

the table looks great though, and i will try to apply the same formula to similar problems and see if it works.

if i have some problems, do you mind if i contact you again here on this community?

thank you so much for the timebeing.

amazing work!

i thank everyone that tried to help me to solve this problem, it means a lot.

cheers,

ricardo