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Finding the Fourth Proportional to 805.64, 1,209.42 and 691.40

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Solution

The fourth proportional to 805.64, 1,209.42 and 691.40 is: 1,037.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.64 : 1,209.42 = 691.40 : x
  2. Step 2: Convert to fraction form
    805.64/1,209.42 = 691.40/x
  3. Step 3: Cross multiply
    805.64x = 1,209.42 × 691.40
  4. Step 4: Simplify right side
    805.64x = 836,192.99
  5. Step 5: Solve for x
    x = 836,192.99/805.64
  6. Step 6: Final answer
    x = 1,037.92

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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.