Answer:
Riverside had the greatest rainfall total
Explanation:
The total amount of rain in a city will be the sum of products of rain amount and days that got that amount. The city with the largest sum got the most rain. The difference in rainfall can be found by subtracting the lesser amount from the greater.
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Riverside
Total rainfall in Riverside was ...
(1/8)×1 +(2/8)×3 +(3/8)×3 +(4/8)×1 +(5/8)×1
= (1 +6 +9 +4 +5)/8 = 25/8 = 3 1/8 . . . . inches
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Little Falls
Total rainfall in Little Falls was ...
(1/8)×1 +(3/8)×1 +(4/8)×1 +(6/8)×2
= (1 +3 +4 +12)/8 = 20/8 = 2 1/2 . . . . inches
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Riverside had more rainfall, because 3 1/8 is more than 2 1/2.
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Without calculation
You can "cancel" dots that are in the same place on each plot. Doing so leaves Riverside with 3 dots at 2/8, 2 dots at 3/8, and 1 dot at 5/8. The remaining dots on the Little Falls plot are the 2 dots at 6/8.
The 3 dots at 2/8 add up to 6/8, as do the 2 dots at 3/8 on the Riverside plot. These two 6/8 values cancel the two 6/8 dots on the Little Falls plot. That leaves one uncancelled dot at 5/8 on the Riverside plot, indicating more rain fell at Riverside.