(b) The time-dependence of the logarithm y of the number of radioactive nuclei in a sample is given by
y = yo - Xt,
where A is known as the decay constant. In the table y is given for a number of values of t. Use a linear fit to calculate the decay constant of the given isotope correct to one decimal. (8)
t (min) 1 2 3 4
y 7.40 7.35 7.19 6.93