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Finding the Fourth Proportional to 1,310.39, 1,808.30 and 712.86

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Solution

The fourth proportional to 1,310.39, 1,808.30 and 712.86 is: 983.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,310.39 : 1,808.30 = 712.86 : x
  2. Step 2: Convert to fraction form
    1,310.39/1,808.30 = 712.86/x
  3. Step 3: Cross multiply
    1,310.39x = 1,808.30 × 712.86
  4. Step 4: Simplify right side
    1,310.39x = 1,289,059.74
  5. Step 5: Solve for x
    x = 1,289,059.74/1,310.39
  6. Step 6: Final answer
    x = 983.72

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.