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Finding the Fourth Proportional to 511.80, 763.64 and 430.80

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Solution

The fourth proportional to 511.80, 763.64 and 430.80 is: 642.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    511.80 : 763.64 = 430.80 : x
  2. Step 2: Convert to fraction form
    511.80/763.64 = 430.80/x
  3. Step 3: Cross multiply
    511.80x = 763.64 × 430.80
  4. Step 4: Simplify right side
    511.80x = 328,973.96
  5. Step 5: Solve for x
    x = 328,973.96/511.80
  6. Step 6: Final answer
    x = 642.78

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.