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Finding the Fourth Proportional to 657.60, 986.72 and 620.80

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Solution

The fourth proportional to 657.60, 986.72 and 620.80 is: 931.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    657.60 : 986.72 = 620.80 : x
  2. Step 2: Convert to fraction form
    657.60/986.72 = 620.80/x
  3. Step 3: Cross multiply
    657.60x = 986.72 × 620.80
  4. Step 4: Simplify right side
    657.60x = 612,555.78
  5. Step 5: Solve for x
    x = 612,555.78/657.60
  6. Step 6: Final answer
    x = 931.50

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Double scale
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.