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Finding the Fourth Proportional to 657.12, 985.68 and 272.40

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Solution

The fourth proportional to 657.12, 985.68 and 272.40 is: 408.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    657.12 : 985.68 = 272.40 : x
  2. Step 2: Convert to fraction form
    657.12/985.68 = 272.40/x
  3. Step 3: Cross multiply
    657.12x = 985.68 × 272.40
  4. Step 4: Simplify right side
    657.12x = 268,499.23
  5. Step 5: Solve for x
    x = 268,499.23/657.12
  6. Step 6: Final answer
    x = 408.60

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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.