Assignment UNIT -1

Submission Date: 6/8/2010

Assignment of MEAN

1. Twelve students were given a math test, and the times (in minutes) to complete it are listed below. Find the range of these times.


10, 9, 12, 11, 8, 15, 9, 7, 8, 6, 12, 10



2. A relay race was completed by 7 participants, and their race times are given below (in seconds). What is the range of race times?

13.2, 14.5, 12.9, 13.9, 15.6, 14.1, 12.3



3. What is the mean test score for the 6 scores listed below?

89, 93, 87, 86, 85, 94



4. The average annual wind speed for the 5 windiest cities in the U.S. is given below in miles per hour. What is the mean of these annual wind speeds?

15.4, 14.0, 13.5, 13.1, 12.9



5.Calculate arithmetic mean from the following data :
Marks (less than) : 80 70 60 50 40 30 20 10

No. of students : 100 90 80 60 32 20 13 5



6.The monthly profits in $ of 100, shops are distributed as follows :

Profit per shop: 0—100 0—200 0—300 0—400 0—500 0—600

No. of shop : 12 30 57 77 94 100



7.Income groups : 150—300 300—500 500—800 800—1200 1200—1800
   No. of firms :     40 32 26 28 42
   Average No .: of workers 8 12 7.5 8.5 4

Find the average salary paid in the whole market.

8.Find the missing frequency from the following data :


Marks  Frequency

5—10   12

10—15 16

15—20  5

20—25  14

25—30  10

30—35  8





9. The following is the frequency distribution of the marks obtained by 250 students in an examination. Compute the mean, the median and the mode.


Marks obtained No. of students Marks obtained No. of students

0—10     15  40—50  12

10—20   20  50—60  31

20—30   24  60—70  71

30-40     24  70—80  52