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Finding the Fourth Proportional to 520.25, 780.12 and 155

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Solution

The fourth proportional to 520.25, 780.12 and 155 is: 232.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.25 : 780.12 = 155 : x
  2. Step 2: Convert to fraction form
    520.25/780.12 = 155/x
  3. Step 3: Cross multiply
    520.25x = 780.12 × 155
  4. Step 4: Simplify right side
    520.25x = 120,918.60
  5. Step 5: Solve for x
    x = 120,918.60/520.25
  6. Step 6: Final answer
    x = 232.42

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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.