Question

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 |

Is it correct to say that in a histogram, the area of each rectangle is proportional to the class size of the corresponding class interval? If not, correct the statement.