9Math Q07-1001
Chapter 7
Introduction to Statics and Probability
- The mean of a , 5a, 9a is 15. The mean of a, 3a, 5a, 7a is
A.4 B.6 C.9 D. 12 E.15 - The mean of 27 numbers is x. If each of 27 numbers is increased by 81 , the increase in the
mean is
A. 3 B. 9 C. 27 D. 81 E. x - The mean height of 6 boys is 4´2´´ . The mean height ot 4 girls is 3´9´´ .The mean height of
combined 6 boys and 4 girls is
A.4´1´´ B.4´ C. 3´11´´ D.3´10´´ E. 412´ - For the sample 5,6,5,7,8,5,6,7,6,5 which of the following is (are) true?
- The median is 6 2. the mean is 6 3. the mode is 5.
A. 1 only B.2 only C. 3 only D. 1 and 3 only E. 1 , 2 and 3
- The median is 6 2. the mean is 6 3. the mode is 5.
- For the sample 9,8,10,9,11,9,12,12 which of the following is (are) false?
1.the mean is 10 2. the median is 10 3. the mode is 9
A.1 only B. 2 only C. 3 only D. 1 and 3 only E. 2 and 3 only - During a season, the goals scored by a school , football team in 20 matches were as follow;
Goals scored in a match 0 1 2 3 4 5
Frequency 2 6 5 3 3 1
The mean number of goals scored was
A.1 B.2 C.2.1 D.2.5 E.3
7.The mean of five numbers is 10 and the mean of two of them is 13. The mean of the
remaining three is
A. 7 B.8 C. 12 D.23 E.24
- There are seven numbers arranged in row, whose mean is 11. The mean numbers of first four
numbers is 8 and the last four number is 14. Then the median of the arrangement is
A.9 B.10 C.11 D.12 E.13