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Finding the Fourth Proportional to 520.88, 780.60 and 399.08

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Solution

The fourth proportional to 520.88, 780.60 and 399.08 is: 598.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.88 : 780.60 = 399.08 : x
  2. Step 2: Convert to fraction form
    520.88/780.60 = 399.08/x
  3. Step 3: Cross multiply
    520.88x = 780.60 × 399.08
  4. Step 4: Simplify right side
    520.88x = 311,521.85
  5. Step 5: Solve for x
    x = 311,521.85/520.88
  6. Step 6: Final answer
    x = 598.07

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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.