Question

The length of 40 leaves of a plant are measured correct to one millimetre, and the obtained data is represented in the following table: | Length (in mm) | Number of leaves | |----------------|------------------| | 118 - 126 | 3 | | 127 - 135 | 5 | | 136 - 144 | 9 | | 145 - 153 | 12 | | 154 - 162 | 5 | | 163 - 171 | 4 | | 172 - 180 | 2 | (i) Draw a histogram to represent the given data. [Hint: First make the class intervals continuous] (ii) Is there any other suitable graphical representation for the same data? (iii) Is it correct to conclude that the maximum number of leaves are 153 mm long? Why?

The following table gives the life times of 400 neon lamps: | Life time (in hours) | Number of lamps | |----------------------|-----------------| | 300 - 400 | 14 | | 400 - 500 | 56 | | 500 - 600 | 60 | | 600 - 700 | 86 | | 700 - 800 | 74 | | 800 - 900 | 62 | | 900 - 1000 | 48 | (i) Represent the given information with the help of a histogram. (ii) How many lamps have a life time of more than 700 hours?

Find the mode of the following frequency distribution : | Class | 10 − 20 | 20 − 30 | 30 − 40 | 40 − 50 | 50 − 60 | |-------|---------|---------|---------|---------|----------| | Frequency | 15 | 10 | 12 | 17 | 4 |

Find the mode of the given frequency distribution : | Class | Frequency | |-------|----------| | 15 – 25 | 6 | | 25 – 35 | 11 | | 35 – 45 | 22 | | 45 – 55 | 23 | | 55 – 65 | 14 | | 65 – 75 | 5 |