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Finding the Fourth Proportional to 520.39, 780.57 and 135.64

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Solution

The fourth proportional to 520.39, 780.57 and 135.64 is: 203.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.39 : 780.57 = 135.64 : x
  2. Step 2: Convert to fraction form
    520.39/780.57 = 135.64/x
  3. Step 3: Cross multiply
    520.39x = 780.57 × 135.64
  4. Step 4: Simplify right side
    520.39x = 105,876.51
  5. Step 5: Solve for x
    x = 105,876.51/520.39
  6. Step 6: Final answer
    x = 203.46

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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.