# FRANK Solutions for Class 9 Maths Chapter 22 - Statistics

Find out how to interpret data from a frequency table by practising TopperLearning’s Frank Solutions for ICSE Class 9 Mathematics Chapter 22 Statistics. Learn to determine class limits based on frequency distribution data. Revise textbook solutions on how to construct a cumulative frequency distribution table.

Study the definition of secondary data, primary data, frequency, variate, class mark, etc. with our Frank textbook solutions. There are ample e-learning resources other than textbook solutions available on our study portal. The learning materials like ICSE Class 9 Maths videos and online mock tests can be used to prepare well for your exam.

## Chapter 22 - Statistics Exercise Ex. 22.1

Find the actual (or true) lower and upper class limits and class-marks (or mid values) of the following classes: 2.1 - 4.0, 4.1 - 6.0 and 6.1 - 8.0.

Observe the given frequency table to answer the following:

Class Interval |
20-24 |
25-29 |
30-34 |
35-39 |
40-44 |
45-49 |

Frequency |
6 |
12 |
10 |
15 |
9 |
2 |

a. The true class limits of the fifth class.

b. The size of the second class.

c. The class boundaries of the fourth class.

d. The upper and lower limits of the sixth class.

e. The class mark of the third class.

## Chapter 22 - Statistics Exercise Ex. 22.2

Construct a frequency distribution table from the given cumulative frequency distribution showing the weights of 750 students in a school:

Weight (in kg) |
c.f. |

More Than 25 |
750 |

More Than 30 |
640 |

More Than 35 |
615 |

More Than 40 |
485 |

More Than 45 |
370 |

More Than 50 |
220 |

More Than 55 |
124 |

More Than 60 |
49 |

More Than 65 |
24 |

More Than 70 |
0 |

a. Find the number of students whose weight lie in the interval 40-45

b. Find the interval which has the most number of students.

Frequency distribution table is as follows:

Weight (in kg) |
c.f. |

25 - 30 |
110 (750 - 640) |

30 - 35 |
25 (640 - 615) |

35 - 40 |
130 (615 - 485) |

40 - 45 |
115 (485 - 370) |

45 - 50 |
150 (370 - 220) |

50 - 55 |
96 (220 - 124) |

55 - 60 |
75 (124 - 49) |

60 - 65 |
25 (49 - 25) |

65 - 70 |
24 (24 - 0) |

70 - 75 |
0 |

a. The number of students whose weight lie in the interval 40 - 45 is 115.

b. The interval 45 - 50 has the most number of students.

## Chapter 22 - Statistics Exercise Ex. 22.3

The daily maximum relative humidity (in per cent) in Mumbai from May 1 to May 7, 1992 is given below:

64, 70, 65, 80, 75, 78

Find the mean.

The mean of 16 natural numbers is 48. Find the resulting mean, if each of the number is

a. increased by 5

b. decreased by 8

c. multiplied by 4

d. divided by 0.25

e. increased by 50%

f. decreased by 10%

The mean of 4 observations is 20. If one observation is excluded, the mean of the remaining observations becomes 15. Find the excluded observation.

The mean monthly income of 8 men is Rs. 8079.75. A man whose monthly income is Rs. 8280 has also been taken into consideration. Calculate the mean monthly income of all the men.

The mean of 200 observations is 20. It is found that the value of 180 is wrongly copied as 280. Find the actual mean.

The following data has been arranged in ascending order.

0, 1, 2, 3, x + 1, x + 5, 20, 21, 26, 29.

Find the value of x, if the median is 5.

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