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Finding the Fourth Proportional to 1,239.60, 1,860.48 and 509.70

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Solution

The fourth proportional to 1,239.60, 1,860.48 and 509.70 is: 764.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,239.60 : 1,860.48 = 509.70 : x
  2. Step 2: Convert to fraction form
    1,239.60/1,860.48 = 509.70/x
  3. Step 3: Cross multiply
    1,239.60x = 1,860.48 × 509.70
  4. Step 4: Simplify right side
    1,239.60x = 948,286.66
  5. Step 5: Solve for x
    x = 948,286.66/1,239.60
  6. Step 6: Final answer
    x = 764.99

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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.