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Finding the Fourth Proportional to 805.13, 1,206.87 and 285

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Solution

The fourth proportional to 805.13, 1,206.87 and 285 is: 427.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.13 : 1,206.87 = 285 : x
  2. Step 2: Convert to fraction form
    805.13/1,206.87 = 285/x
  3. Step 3: Cross multiply
    805.13x = 1,206.87 × 285
  4. Step 4: Simplify right side
    805.13x = 343,957.95
  5. Step 5: Solve for x
    x = 343,957.95/805.13
  6. Step 6: Final answer
    x = 427.21

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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.