The following graph shows the temperature of a patient in a hospital, recorded every hour. (a) What was the patient's temperature at 1 p.m.?

In the graph, x-axis represents the time and y-axis represents the temperature of the patient. Scale: On x-axis 1cm=1 hr On y-axis 1cm=1 ℃
Steps:

1. To find the temperature at a particular time: Trace the vertical line parallel to y-axis passing from the time point on x-axis, find the point where this vertical line intersects the graph. Now from that point trace a horizontal line parallel to x-axis, this line intersects the y-axis at the required point.
2. To find the time at a particular temperature: Trace the horizontal line parallel to x-axis passing from the temperature point on y-axis, find the point where this horizontal line intersects the graph. Now from that point trace a vertical line parallel to y-axis, this line intersects the x-axis at the required point.
   Now,
   a) Follow step 1 to find temperature corresponding to time 1 pm, you get a point between 36 to 37 which is 36.5 ℃
   b) Follow step 2 from a point between 38℃ i.e. 38.5 ℃, we get the corresponding point on x-axis which is 12 noon.
   c) In the graph we see 36.50℃ is the temperature which is the same. Follow step 2 to get corresponding times which is 1 and 2 pm.
   d) Temperature at 1:30 pm is 36.50℃, since we know from (c) temperature is the same between interval 1 pm to 2 pm.
   e) To show upward trend graph continues with positive slope, we have 9 am, 10 am, and 2 pm time interval where the slope is positive. So patient's temperature showing upward trend in 9 am and 2 pm interval.