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Finding the Fourth Proportional to 811.59, 1,214.64 and 487.19

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Solution

The fourth proportional to 811.59, 1,214.64 and 487.19 is: 729.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.59 : 1,214.64 = 487.19 : x
  2. Step 2: Convert to fraction form
    811.59/1,214.64 = 487.19/x
  3. Step 3: Cross multiply
    811.59x = 1,214.64 × 487.19
  4. Step 4: Simplify right side
    811.59x = 591,754.39
  5. Step 5: Solve for x
    x = 591,754.39/811.59
  6. Step 6: Final answer
    x = 729.13

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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.