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Finding the Fourth Proportional to 778, 1,073.64 and 428.72

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Solution

The fourth proportional to 778, 1,073.64 and 428.72 is: 591.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    778 : 1,073.64 = 428.72 : x
  2. Step 2: Convert to fraction form
    778/1,073.64 = 428.72/x
  3. Step 3: Cross multiply
    778x = 1,073.64 × 428.72
  4. Step 4: Simplify right side
    778x = 460,290.94
  5. Step 5: Solve for x
    x = 460,290.94/778
  6. Step 6: Final answer
    x = 591.63

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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.