Exercise 13.1

1. The following graph shows the temperature of a patient in a hospital, recorded every hour.

Instruction

(a) What was the patient’s temperature at 1 p.m. ? °C

(b) When was the patient’s temperature 38.5°C?

(c) The patient’s temperature was the same two times during the period given. What were these two times? Same between and

(d) What was the temperature at 1.30 p.m.? How did you arrive at your answer? °C.

Since, 1.30 p.m is from the two points: p.m. and p.m i.e. it is the .

Similarly, the point on the y-axis, between 36 °C and 37 °C, represents 36.5 °C.

(e) During which periods did the patients’ temperature showed an upward trend? Time Periods: a.m. to a.m. and from p.m. to p.m.

2. The following line graph shows the yearly sales figures for a manufacturing company.

(a) What were the sales in (i) 2002 (ii) 2006?

(i) 2002: crores (ii) 2006: crores

(b) What were the sales in (i) 2003 (ii) 2005?

(i) 2003: crores (ii) 2005: crores

(c) Compute the difference between the sales in 2002 and 2006.

The difference in the sales of 2002 and 2006 is crores.

(d) In which year was there the greatest difference between the sales as compared to its previous year?

Solution:

(a) From the above graph we can conclude that:

Sales in 2002 = 4 crores

Sales in 2006 = 8 crores

Sales in 2003 = 7 crores

Sales in 2005 = 10 crores

(b) From the graph we can see that:

Sales in 2002 = 4 crores and

Sales in 2006 = 8 crores

Therefore,

Difference of sales = 8 - 4 = Rs. 4 crores

(c) We can observe that the year 2005 has the greatest difference in sales compared to its previous year (2004) with the difference being 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.

(a) How high was Plant A after:

(i) 2 weeks cm

(ii) 3 weeks ? cm

(b) How high was Plant B after:

(i) 2 weeks cm

(ii) 3 weeks? cm

(c) How much did Plant A grow during the 3rd week? cm

(d) How much did Plant B grow from the end of the 2nd week to the end of the 3rd week? cm

(e) During which week did Plant A grow most?

(f) During which week did Plant B grow least?

(g) Were the two plants of the same height during any week shown here? Specify

Solution:

(a) From the above graph we can conclude:

(i) Plant A is 7 cm long after 2 weeks.

(ii) Plant A is 9 cm long after 3 weeks.

(b)

(i) Plant B is 7 cm long after 2 weeks.

(ii) Plant B is 10 cm long after 3 weeks.

(d) Plant B grew by 10 cm (3rd week end ) – 7 cm (2nd week end) = 3 cm

(e) Plant A grew the most during the second week (difference of 5 cm).

(f) Plant B grew the least during first week (only 1 cm height gain).

(g) We can see that at the end of the second week, plants A and B were of the same height, that is 7 cm.

4. The following graph shows the temperature forecast and the actual temperature for each day of a week.

Instruction

(a) On which days was the forecast temperature the same as the actual temperature? The number of days the forecast temperature was the same as the actual temperature:

These days were , and .

(b) What was the maximum forecast temperature during the week? °C

(c) What was the minimum actual temperature during the week? °C

(d) On which day did the actual temperature differ the most from the forecast temperature?

5. Use the tables below to draw linear graphs.

(a) The number of days a hill side city received snow in different years

Year	Days
2003	8
2004	10
2005	5
2006	12

Join the coloured data points with straight lines.

(b) Population (in thousands) of men and women in a village in different years.

Year	Number of Men	Number of Women
2003	12	11.3
2004	12.5	11.9
2005	13	13
2006	13.2	13.6
2007	13.5	12.8

Instructions

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.