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Finding the Fourth Proportional to 521.10, 780.75 and 315.18

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Solution

The fourth proportional to 521.10, 780.75 and 315.18 is: 472.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.10 : 780.75 = 315.18 : x
  2. Step 2: Convert to fraction form
    521.10/780.75 = 315.18/x
  3. Step 3: Cross multiply
    521.10x = 780.75 × 315.18
  4. Step 4: Simplify right side
    521.10x = 246,076.79
  5. Step 5: Solve for x
    x = 246,076.79/521.10
  6. Step 6: Final answer
    x = 472.23

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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.