A sample analysis of examination results of 500 students was made. It was found that 220 students had failed, 170 had secured a third class, 90 were placed in second class and 20 got a first class....

Extracted text: A sample analysis of examination results of 500 students was made. It was found that 220 students had failed, 170 had secured a third class, 90 were placed in second class and 20 got a first class. Are there figures commensurate with the general examination result which is in the ratio of 4: 3:21 for the various categories respectively. (The table value of x² for 3 d.f. at 5% level of significance is 7.81).