CLASS-10

BOARD: CBSE

Mathematic Worksheet - 13

TOPIC: Measures or Central tendency

For other **CBSE Worksheet for class 10 Mathematic** check out main page of Entrancei.

**FORMULAE**

1. Mean ( x) = (x
3. Mean (x ) = A + ∑f
2. Mean ( x ) = ∑f
4.Mean ( x) = A +h(∑f
5 . a) If n is odd, then Median = the value of ((n+1)/2)
b. If n is even, then Median =(the value of (n/2) |

**1. If the mean of the numbers 15, 20, a, 32, b is 25, find b in terms of a.**

**2. The mean of 11 results is 30. If the mean of first 6 results is 28 and that of the last 6 results is 32, find the 6 ^{th} results.**

**3. The mean weight of a class of 35 students is 45 kg. If the weight of the teacher be included the mean weight increases by 500 g. find the weight of the teacher.**

**4. If the median of 11, 12, 14, 18, x +2, x + 4, 30, 32, 35, 41 is 24, find the value of x.**

**5. The mean of 30 values is 150, if 2 is subtracted from every number, what will be the new mean ?**

**6. Find the median of:**

19, 25, 59, 48, 35, 31, 30, 32, 51.If 25 is replaced by 52, find the new median.

**7. For what value of p, the mode of following data is 5 :**

1, 2, 5, 7, 5, 2, 7, 5, 9, 2, 3, p, 11.

**8. The mean of the following frequency table is 50. But the frequenciesf _{1}and f_{2 }in the class 20-40 and 60-80 are missing. Find the value of f_{1} and f_{2}.**

Class |
0-20 |
20-40 |
40-60 |
60-80 |
80-100 |
Total |

Frequency |
17 |
f |
32 |
f |
19 |
120 |

**9. Find the mode of the following distribution by drawing a histogram.**

Daily wages(in Rs) |
31-36 |
37-42 |
43-48 |
49-54 |
55-60 |
61-65 |

No. of workers |
6 |
12 |
20 |
15 |
9 |
4 |

**10.The frequency distribution of weights of a group of 80 students in a class in a school is given below :**

Weights(in kg) |
40-44 |
45-49 |
50-54 |
55-59 |
60-64 |
65-69 |
70-74 |

No. of students |
5 |
8 |
14 |
20 |
16 |
10 |
7 |

Draw the histogram and find the modal weight.

**ANSWERS**

1) b= 58-a

2) 30

3) 63 kg

4) x= 21

5) 148

6) 32, 35

7) p=5

8) =28 = 24

9) Rs. 46.5

10) 57.5 kg