Exercise 15.1
1. The following graph shows the temperature of a patient in a hospital, recorded every hour.
What was the patient’s temperature at 1 p.m.?
When was the patient’s temperature 38.5°?
The patient’s temperature was the same two times during the period given. What were these two times?
What was the temperature at 1.30 p.m.? How did you arrive at your answer?
During which periods did the patient’s temperature show an upward trend?
Exercise 15.1
1. The following graph shows the temperature of a patient in a hospital, recorded every hour.
What was the patient’s temperature at 1 p.m.?
When was the patient’s temperature 38.5°?
The patient’s temperature was the same two times during the period given. What were these two times?
What was the temperature at 1.30 p.m.? How did you arrive at your answer?
During which periods did the patient’s temperature show an upward trend?
Explanation:
The patient's temperature was 36.5°C at around 1 o'clock.
(A) The patient's temperature was 38.5°C at 12 o'clock.
The patient's temperature remained constant between 1 and 2 p.m.
It's 36.5 °C outside at 1.30 p.m.
The distance between the two points denoting 1 p.m. and 2 p.m. on the x-axis is equal to those distances. Thus, it is now 1.30 p.m. Likewise, 36.50 C is represented by the y-axis position between 360 and 370 C.
From 9 to 11 in the morning and from 2 to 3 in the afternoon, the patient's fever climbed.
2. The following line graph shows the yearly sales figures for a manufacturing company.
What were the sales in (i) 2002 (ii) 2006?
What were the sales in (i) 2003 (ii) 2005?
Compute the difference between the sales in 2002 and 2006.
In which year was there the greatest difference between the sales as compared to the previous year?
2. The following line graph shows the yearly sales figures for a manufacturing company.
What were the sales in (i) 2002 (ii) 2006?
What were the sales in (i) 2003 (ii) 2005?
Compute the difference between the sales in 2002 and 2006.
In which year was there the greatest difference between the sales as compared to the previous year?
Explanation:
The revenue from
It cost Rs. 4 crores in 2002 and Rs. 8 crores in 2006.
The revenue in
The amounts in (i) 2003 were 7 crores and (ii) 2005 were 10 crores.
The sales gap between 2002 and 2006 is equal to 8 crores minus 4 crores, or 4 crores.
The biggest difference in sales between 2005 and its predecessor year was (Rs. 10 crores -Rs. 6 crores) = Rs. 4 crores.
3. For an experiment in Botany, two different plants, plant A and plant B, were grown under similar laboratory conditions. Their heights were measured at the end of each week for 3 weeks. The results are shown by the following graph.
How high was Plant A after (i) 2 weeks (ii) 3 weeks?
How high was Plant B after (i) 2 weeks (ii) 3 weeks?
How much did Plant A grow during the 3rd week?
How much did Plant B grow from the end of the 2nd week to the end of the 3rd week?
During which week did Plant A grow most?
During which week did Plant B grow least?
Were the two plants of the same height during any week shown here? Specify.
3. For an experiment in Botany, two different plants, plant A and plant B, were grown under similar laboratory conditions. Their heights were measured at the end of each week for 3 weeks. The results are shown by the following graph.
How high was Plant A after (i) 2 weeks (ii) 3 weeks?
How high was Plant B after (i) 2 weeks (ii) 3 weeks?
How much did Plant A grow during the 3rd week?
How much did Plant B grow from the end of the 2nd week to the end of the 3rd week?
During which week did Plant A grow most?
During which week did Plant B grow least?
Were the two plants of the same height during any week shown here? Specify.
Explanation:
(a)
After two weeks, Plant A measured 7 cm in height.
It was 9 cm high after three weeks.
(b)
Two weeks later, Plant B was also 7 cm tall.
It was 10 cm tall after 3 weeks.
On the third week, Plant A grew by 9 cm, 7 cm, and 2 cm.
Plant B increased by 10cm-7cm (3 cm) from the end of the second week to the end of the third week.
e) On the second week, Plant A grew the most.
(f) In the first week, Plant B grew the least
(g) Yes. Plants A and B were 7 cm in height at the conclusion of the second week.
4. The following graph shows the temperature forecast and the actual temperature for each day of the week.
On which days was the forecast temperature the same as the actual temperature?
What was the maximum forecast temperature during the week?
What was the minimum actual temperature during the week?
On which day did the actual temperature differ the most from the forecast temperature?
4. The following graph shows the temperature forecast and the actual temperature for each day of the week.
On which days was the forecast temperature the same as the actual temperature?
What was the maximum forecast temperature during the week?
What was the minimum actual temperature during the week?
On which day did the actual temperature differ the most from the forecast temperature?
Explanation:
(A) On Tuesday, Friday, and Sunday, the forecasted and actual temperatures coincided.
The forecasted high temperature was 35 °C.
The real minimum temperature was 15 °C .
Thursday had the biggest difference between the actual and predicted temperatures.
5. Use the tables below to draw linear graphs
The number of days a hillside city received snow in different years.
Population (in thousands) of men and women in a village in different years.
5. Use the tables below to draw linear graphs
The number of days a hillside city received snow in different years.
Population (in thousands) of men and women in a village in different years.
Explanation:
Imagine an axis with "Years" on it and "Days" on the other. The linear graph will appear as follows using the provided data:
Consider the axes for "Years" (on the x-axis) and "No. of Men and No. of Women" (on the y-axis) (2 graphs). With the supplied information, the linear graph will look like follows:
6. A courier person cycles from a town to a neighbouring suburban area to deliver a parcel to a merchant. His distance from the town at different times is shown by the following graph.
What is the scale taken for the time axis?
How much time did the person take for the travel?
How far is the place of the merchant from the town?
Did the person stop on his way? Explain.
During which period did he ride fastest?
6. A courier person cycles from a town to a neighbouring suburban area to deliver a parcel to a merchant. His distance from the town at different times is shown by the following graph.
What is the scale taken for the time axis?
How much time did the person take for the travel?
How far is the place of the merchant from the town?
Did the person stop on his way? Explain.
During which period did he ride fastest?
Explanation:
4 units equal 1 hour.
The trip time was three and a half hours.
The town was 22 kilometres away.
The horizontal axis of the graph has shown that this is the case. He remained there from 10 am to 10.30 am.
He travels the quickest between 8 and 9 in the morning.
7. Can there be a time-temperature graph as follows? Justify your answer.
7. Can there be a time-temperature graph as follows? Justify your answer.
Explanation:
It is a graph of temperature with time.As time goes on, it is displaying the rise in temperature.
It is a graph of temperature over time. As the time goes on, the temperature is decreasing.
The graph figure (iii) is illogical because the temperature is rising so quickly and this is unachievable.
It is a graph of temperature and time. The temperature is staying consistent.
Also Read: Introduction to Graphs Extra Questions - Class 8
