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Finding the Fourth Proportional to 515.80, 772.80 and 429.69

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Solution

The fourth proportional to 515.80, 772.80 and 429.69 is: 643.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.80 : 772.80 = 429.69 : x
  2. Step 2: Convert to fraction form
    515.80/772.80 = 429.69/x
  3. Step 3: Cross multiply
    515.80x = 772.80 × 429.69
  4. Step 4: Simplify right side
    515.80x = 332,064.43
  5. Step 5: Solve for x
    x = 332,064.43/515.80
  6. Step 6: Final answer
    x = 643.79

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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.