# A Line Graph

A line graph displays data that changes continuously over periods of time.

Time |
6 a.m. | 10 a.m. | 2 p.m. | 6 p.m. |

TemperatureÂ° C |
22 | 25 | 27 | 23 |

The above table shows the temperature of Chennai city, taken every four hours for a day. We call this as time-temperature graph. The horizontal line (*x*-axis) shows the timings at which the temperatures were recorded. The vertical line (*y*-axis) denotes the temperature.

The temperature for every four hours is recorded and plotted as points as shown in the graph. These points are connected by line segments. The result is line graph. From the graph, in between 10 a.m. and 2 p.m. we can find that the temperature was increased by 2Â° C.

The given graph represents the scores of two groups of class VIII students in a test of reading ability. Study the graph and answer the following questions.

(i) What information is given on the two axes?

(ii) Which line shows the marks scored by group A?

(iii) How many of them got more than 50%?

(i) The horizontal axis (or the *x*-axis) represent class marks. The vertical axis represent the performance of Group A & Group B. dotted line indicates the performance of Group B. Dark line indicates the performance of Group A.

(ii) Dark line shows the marks scored by Group A.

(iii) 2 of them got more than 50%.

The given graph describes the distances of a bus from a Chennai at different times when it is travelling from chennai to Chidambaram, which are 300 km apart. Study the graph and answer the following.

(i) What information is given on the two axes?

(ii) When did the bus begin its journey?

(iii) How far did the bus go in the first hour?

(iv) How far did the bus go during (i) the 2^{nd} hour (ii) the 3^{rd} hour?

(v) Was the speed same during the first three hours? How do you know it?

x-axis shows the time, *y*-axis shows the distance from Chennai.

The bus started from Chennai at 8 a.m.

The bus travelled 50 km during the first hour.

The distance covered by he bus during

(a) the 2^{nd} hour is (150 km - 50 km) 100 km

(b) the 3^{rd} hour is (200 km - 150 km) 50 km.

The speed of the bus was not the same all the time since the distance travelled by the bus in each hour is different.