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Finding the Fourth Proportional to 520.25, 780.38 and 135.50

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Solution

The fourth proportional to 520.25, 780.38 and 135.50 is: 203.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.25 : 780.38 = 135.50 : x
  2. Step 2: Convert to fraction form
    520.25/780.38 = 135.50/x
  3. Step 3: Cross multiply
    520.25x = 780.38 × 135.50
  4. Step 4: Simplify right side
    520.25x = 105,741.49
  5. Step 5: Solve for x
    x = 105,741.49/520.25
  6. Step 6: Final answer
    x = 203.25

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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.