To determine the type of sequence represented by the number of onions used on each day, let's list the values:
- Thursday: 187
- Friday: 173
- Saturday: 156
- Sunday: 136
Now, we'll examine the differences between consecutive days:
- From Thursday to Friday: 173 - 187 = -14
- From Friday to Saturday: 156 - 173 = -17
- From Saturday to Sunday: 136 - 156 = -20
The differences are:
-14, -17, -20
Next, let's look at the differences of these differences:
- From -14 to -17: -17 - (-14) = -3
- From -17 to -20: -20 - (-17) = -3
The second differences are constant at -3.
Since the first differences are not constant (they vary) but the second differences are constant, this indicates that the initial set of numbers forms a quadratic sequence.
In summary, the sequence of onion usage over the days is a quadratic sequence.