120 surnames were randomly picked up from a local telephone directory And the frequency distribution of the number of - Maths - Statistics

Question

120 surnames were randomly picked up from a local telephone
directory And the frequency distribution of the number of letters
in the English alphabets in the surnames were recorded as ( given
in the below table) If the mean of the data is 7 find the missing
frequencies x and y

Rishabh Mittal · Accepted Answer

Dear Student ,

Please find below the solution to the asked query :

109+x+y=120x+y=11x=11-y   
1Mean=∑fixi∑fi7=742 5+1 5x+16 5y1207×120=742 5+1
5 11-y+16
5y      using 1840=742 5+16 5-1
5y+16 5y840=759+15y840-759=15y81=15yy=8115=5 4x=11-5 4=5
6Number of surnames can't be in decimal please recheck your question
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120 surnames were randomly picked up from a local telephone directory. And the frequency distribution of the number of letters in the English alphabets in the surnames were recorded as. ( given in the below table). If the mean of the. data is 7 find the missing frequencies x and y