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Finding the Fourth Proportional to 1,385.90, 2,078.85 and 1,229.30

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Solution

The fourth proportional to 1,385.90, 2,078.85 and 1,229.30 is: 1,843.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,385.90 : 2,078.85 = 1,229.30 : x
  2. Step 2: Convert to fraction form
    1,385.90/2,078.85 = 1,229.30/x
  3. Step 3: Cross multiply
    1,385.90x = 2,078.85 × 1,229.30
  4. Step 4: Simplify right side
    1,385.90x = 2,555,530.31
  5. Step 5: Solve for x
    x = 2,555,530.31/1,385.90
  6. Step 6: Final answer
    x = 1,843.95

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1.5x scale

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.