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Finding the Fourth Proportional to 515.90, 772.78 and 429.02

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Solution

The fourth proportional to 515.90, 772.78 and 429.02 is: 642.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.90 : 772.78 = 429.02 : x
  2. Step 2: Convert to fraction form
    515.90/772.78 = 429.02/x
  3. Step 3: Cross multiply
    515.90x = 772.78 × 429.02
  4. Step 4: Simplify right side
    515.90x = 331,538.08
  5. Step 5: Solve for x
    x = 331,538.08/515.90
  6. Step 6: Final answer
    x = 642.64

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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.