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Finding the Fourth Proportional to 657.20, 921.70 and 657.20

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Solution

The fourth proportional to 657.20, 921.70 and 657.20 is: 921.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    657.20 : 921.70 = 657.20 : x
  2. Step 2: Convert to fraction form
    657.20/921.70 = 657.20/x
  3. Step 3: Cross multiply
    657.20x = 921.70 × 657.20
  4. Step 4: Simplify right side
    657.20x = 605,741.24
  5. Step 5: Solve for x
    x = 605,741.24/657.20
  6. Step 6: Final answer
    x = 921.70

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Why These Related Problems?

These problems maintain the same ratio (1.40) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.