Test: Measures Of Central Tendency - Class 9 MCQ

The prime numbers between 20 and 30 are 23, 29.
► Mean of 23 and 29 = (23 + 29) / 2 = 52/ 2 = 26

Mean=30 then total sum=30×69=2070 if 5 increase to all then total sum=2070+30×5=2070+150=2220
New mean =2220÷30 =74

The difference between the maximum & minimum value of the observation is called as range.
So Range = 99-47 = 52

The number of observation is 25. The mean is 32.
► The sum = 25 + 25 + 25... 32 times
► 32*25 = 800

Mean = sum of all obs. /no. of obs.
► 8 = (6+4+7+x+10)/5
► 40 = 27+x
► x = 13

• The mode is the most frequently occurring value of data.
• Here 4 is the most frequently occurring observation. So 4 is the mode of the data.

Arranging the given terms in descending order 15, 12, 9, 8, 7, 6, 5, 5, 3
► Number of terms = 9
► Median = (n+1)/2 = 10/2 = 5^th term = 7

Arranging the data in ascending order, we have:
29, 34, 37, 41, 45, 54, 63, 70, 70, 83
Here, the number of observations, n = 10 (Even).

Hence, the median of the given data is 49.5.

► Mean = sum of all the obs./ no. of obs.
In the given question number of observation is 5.
► Sum of all observations = 5x + 20 
But x =12; on substituting the value of x we get 5 * 12 + 20 = 80.
► Mean = 80 / 5 = 16

17, 18, 20, 22, x+2, x+4, 31, 35, 37
The total number of observation is 9, which is odd.
► Median  = (9+1)/2^th term = 5^th term
Now 5^th term of the observation is (x+2)
Also given, median = 24
► x + 2 = 24
► x = 24-2
► x = 22
So the value of x is 22.