How to write required output data to workspace in excel sheet format

Hi, I am using Matlab R2014b in mac and i have problem in writing output data in excel sheet. I have

Q=[stressMax1,stressMax2,stressMax3,stressMax4,stressMax5,stressMax6];mean=mean(Q);
standarddeviation=std(Q);

and i have values of all

"stressMax1,stressMax2,stressMax3,stressMax4,stressMax5,stressMax6"

and i want to write these data in excel sheet like in first row labelling

stressMax1,stressMax2,stressMax3,stressMax4,stressMax5,stressMax6, mean, standard deviation

and in second row all the values.Can anyone help me with the code?

i have used

filename= 'MD.xlsx';
sheetname=cell(1,8);

data_list={'stressMax1[MPa],stressMax2[MPa],stressMax3[MPa],stressMax4[MPa],stressMax5[MPa],stressMax6[MPa],mean,standarddeviation'};
xlswrite(filename,data_list,sheet name);

and i am getting an error saying that Error using xlswrite (line 165) Sheet argument must be a string or a whole number greater than 0.

Regards Agastya