Step 1 : Activate Frequency [SM41]
Shift > Mode
Scroll down
Press '4' > Press '1' to turn ON Frequency
Step 2 : Change to Stats mode [M21]
Mode > Press '2' for Stats > Press '1' to choose 1-VAR
Step 3 : Key in data
Key in data for 'x' and 'frequency'
Enter number > Press '='
Once data entry completed,
Press 'AC'
Step 4 : Finding Mean and Standard Deviation [S14]
Shift > Press '1' > Press '4' Var
Press '2' for MEAN > Press '='
Press '3' for STANDARD DEVIATION > Press '='