To find yesterday's temperature, we first need to identify the temperatures for today and the day before yesterday.
- Today's temperature is represented by the point (0, 0), which is 0° Celsius.
- We need to determine the temperature two days ago. The temperatures are plotted at the following points:
- (2, 2) → 2° Celsius
- (-4, 4) → 4° Celsius
- (-3, 0) → 0° Celsius
- (-2, -2) → -2° Celsius
- (0, 0) → 0° Celsius (today)
- (4, -1) → -1° Celsius
Now, we assume the temperature two days ago could be from one of the points that's not today. Let's denote today's temperature (0°) as T_today, yesterday's temperature as T_yesterday, and the temperature two days ago as T_two_days_ago.
According to the problem, the temperature yesterday was right in between today’s temperature and the temperature two days ago. Mathematically, this can be expressed as: \[ T_yesterday = \frac{T_today + T_two_days_ago}{2} \]
We know that:
- T_today = 0°
To find T_two_days_ago, we can test the possible temperatures from the plotted points:
- If T_two_days_ago = 2° Celsius: \[ T_yesterday = \frac{0 + 2}{2} = 1° \text{ Celsius} \]
- If T_two_days_ago = 4° Celsius: \[ T_yesterday = \frac{0 + 4}{2} = 2° \text{ Celsius} \]
- If T_two_days_ago = 0° Celsius: (not valid since it's today)
- If T_two_days_ago = -2° Celsius: \[ T_yesterday = \frac{0 + (-2)}{2} = -1° \text{ Celsius} \]
- If T_two_days_ago = -1° Celsius: \[ T_yesterday = \frac{0 + (-1)}{2} = -0.5° \text{ Celsius} \]
Among the calculated values, the valid options for yesterday's temperature based on available points are:
- 1° Celsius (if yesterday was between 0° and 2°)
- 2° Celsius (if yesterday was between 0° and 4°)
- -1° Celsius (if yesterday was between 0° and -2°)
Since we are looking for a straightforward solution that adheres to the typical interpretation of "right in between" discrete values, and limiting the candidates based on the possibilities we have explored:
The best fit considering common temperatures would be that yesterday's temperature was 1° Celsius.
So, the final answer is: Yesterday’s temperature was 1° Celsius.