Question 1089542
 I have this set
 (100,1)
 (150,2)
 (300,3)
 (650,4)
 (1200,5) 
 When plotted, they form a group which resembles a radical function ( y = sqrt(x) ). What is the specific formula for this radical function and how do I find it?  
:
this looks more like a logarithmic function
Using the form: a*log(x) + b = y find a & b using last and the first given values
a*log(1200) + b = 5  and a*log(100)+b = 1, find the common log of each
3.08a + b = 5 and 2a + b = 1
Use elimination on these two equations to find a
3.08a + b = 5
2.00a + b = 1
---------------subtraction eliminates b, find a
1.08a = 4
a = 4/1.08
a = 3.7
Find b using the equation
3.08(3.7) + b = 5
11.4 + b = 5
b = 5 - 11.4 - 5
b = -6.4
The equation then
f(x) = 3.7log(x) - 6.4
this fits the data fairly closely
100, 1.0
150, 1.7
300, 2.8
650, 4.0
1200, 5.0