In reading a burette to 0.01 ml the final figure has to be estimated. The following frequency table gives the final figures of 50 such readings. Carry out an appropriate significance test to determine whether some digits are preferred to others. 

Digit: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 

Frequency : 1, 6, 4, 5, 3, 11, 2, 8, 3, 7