Business Statistics

Q1 In a test given to 500 students, the average marks was 56 and the standard deviation was 20. Find (i) the number of students exceeding a score of 60.
(ii) the number of students having marks between 50 and 70.
(iii) the value of marks exceeded by the top 100 students.

Answer-------- (i) number of students exceeding a score of 60=210
(ii) The number of students having marks between 50 and 70=188
(iii) The value of marks exceeded by the top 100 students=73

Q2. Following are the scores obtained by 2 students A and B in 10 tests of 100 marks each.
Tests 1 2 3 4 5 6 7 8 9 10
Scores obtained 23 45 37 56 76 57 39 49 67 54 by A
Scores obtained 48 39 76 68 69 56 74 58 65 73 by B
If the consistency of performance is the criterion for awarding a prize, which student should get the prize? Use coefficient of variation to measure the consistency.

Answer-------- student B should get the prize.
COV of A = 28.88%
COV of B=18.42%
Scores of B is more consistent.

Q3. Find the mean and median for the foll . data Class F 5-10 7 10-15 8 15-20 5 20-25 4 25-30 6

Answer ------- mean= 16.5
Median=15

Q4. Find the mode Class F 4-6 3 6-8 5 8-10 10 10-12 6

Answer ------- mode= 9.11

Q5. Find the mean and median for the following data: Class interval Freq. 4 – 8 5 8-12 6 12- 16 7 16-20 2

Answer