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Finding the Fourth Proportional to 762.72, 1,052.68 and 638.20

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Solution

The fourth proportional to 762.72, 1,052.68 and 638.20 is: 880.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    762.72 : 1,052.68 = 638.20 : x
  2. Step 2: Convert to fraction form
    762.72/1,052.68 = 638.20/x
  3. Step 3: Cross multiply
    762.72x = 1,052.68 × 638.20
  4. Step 4: Simplify right side
    762.72x = 671,820.38
  5. Step 5: Solve for x
    x = 671,820.38/762.72
  6. Step 6: Final answer
    x = 880.82

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.