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Finding the Fourth Proportional to 1,865.80, 2,798.98 and 811.90

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Solution

The fourth proportional to 1,865.80, 2,798.98 and 811.90 is: 1,217.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,865.80 : 2,798.98 = 811.90 : x
  2. Step 2: Convert to fraction form
    1,865.80/2,798.98 = 811.90/x
  3. Step 3: Cross multiply
    1,865.80x = 2,798.98 × 811.90
  4. Step 4: Simplify right side
    1,865.80x = 2,272,491.86
  5. Step 5: Solve for x
    x = 2,272,491.86/1,865.80
  6. Step 6: Final answer
    x = 1,217.97

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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.