3a. [7 marks] A calculator generates a random sequence of digits. A sample of 200 digits is randomly selected from the first 100 000 digits of the sequence. The following table gives the number of times each digit occurs in this sample. digit frequency 17 21 15 19 25 27 19 23 18 16 It is claimed that all digits have the same probability of appearing in the sequence. Test this claim at the 5% level of significance. 3b. [2 marks] Explain what is meant by the 5% level of significance.