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Finding the Fourth Proportional to 806.70, 1,114.65 and 639.12

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Solution

The fourth proportional to 806.70, 1,114.65 and 639.12 is: 883.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.70 : 1,114.65 = 639.12 : x
  2. Step 2: Convert to fraction form
    806.70/1,114.65 = 639.12/x
  3. Step 3: Cross multiply
    806.70x = 1,114.65 × 639.12
  4. Step 4: Simplify right side
    806.70x = 712,395.11
  5. Step 5: Solve for x
    x = 712,395.11/806.70
  6. Step 6: Final answer
    x = 883.10

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.