Answer:
Last option is the correct choice.
Step-by-step explanation:
Convert the mixed numbers into fraction and apply the rate formula.
Rate = Change / Unit Time
= 12 1/4 ÷ 3 1/2
= 49/4 ÷ 7/2 (Answer matching with the last option)
= 49/4 x 2/7 (Inverting the second fraction)
= 7/2
= 3 1/2
The rate of change per hour is 3 and a half degrees in temperature.
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