t=[1 2 3 4 5 6 7 8 9 10 11];
C=[0.28 0.399 0.49 0.569 0.636 0.699 0.755 0.809 0.859 0.906 0.951];
logt = log10(t);
logC = log10(C);
p = polyfit(logt,logC,1)
plot(logt,polyval(p,logt), 'r');
hold on;
plot(logt, logC,'k*');
h = legend ('numerical fit', 'Data', 'location', 'southeast');
set (h, "fontsize", 16);
xlabel('log(time)', 'FontSize', 16)
ylabel('log(C/C_0)', 'FontSize', 16)
axis('tight')
set(gca,'FontSize',16)