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Finding the Fourth Proportional to 520.51, 780.78 and 418.45

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Solution

The fourth proportional to 520.51, 780.78 and 418.45 is: 627.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.51 : 780.78 = 418.45 : x
  2. Step 2: Convert to fraction form
    520.51/780.78 = 418.45/x
  3. Step 3: Cross multiply
    520.51x = 780.78 × 418.45
  4. Step 4: Simplify right side
    520.51x = 326,717.39
  5. Step 5: Solve for x
    x = 326,717.39/520.51
  6. Step 6: Final answer
    x = 627.69

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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.