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Finding the Fourth Proportional to 520.95, 780.75 and 212.45

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Solution

The fourth proportional to 520.95, 780.75 and 212.45 is: 318.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.95 : 780.75 = 212.45 : x
  2. Step 2: Convert to fraction form
    520.95/780.75 = 212.45/x
  3. Step 3: Cross multiply
    520.95x = 780.75 × 212.45
  4. Step 4: Simplify right side
    520.95x = 165,866.43
  5. Step 5: Solve for x
    x = 165,866.43/520.95
  6. Step 6: Final answer
    x = 318.39

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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.