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Finding the Fourth Proportional to 520.80, 780.16 and 315.26

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Solution

The fourth proportional to 520.80, 780.16 and 315.26 is: 472.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.80 : 780.16 = 315.26 : x
  2. Step 2: Convert to fraction form
    520.80/780.16 = 315.26/x
  3. Step 3: Cross multiply
    520.80x = 780.16 × 315.26
  4. Step 4: Simplify right side
    520.80x = 245,953.24
  5. Step 5: Solve for x
    x = 245,953.24/520.80
  6. Step 6: Final answer
    x = 472.26

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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.