Row Data Standard Deviation Mock Tests

A row data set shows the number of errors made by four programmers in a week: Programmer A: Mon=3, Tue=5, Wed=2, Thu=4, Fri=6 Programmer B: Mon=4, Tue=3, Wed=5, Thu=2, Fri=4 Programmer C: Mon=3, Tue=3, Wed=3, Thu=4, Fri=4 Programmer D: Mon=5, Tue=2, Wed=4, Thu=3, Fri=5 Which programmer had the most consistent performance (lowest standard deviation)?

A table shows the electricity consumption (in kWh) of three appliances over five months: Refrigerator: 150, 155, 148, 152, 150 Air Conditioner: 300, 320, 350, 340, 330 Fan: 80, 85, 90, 88, 92 Which appliance has the most stable electricity consumption (smallest standard deviation)?