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Finding the Fourth Proportional to 646.72, 891.12 and 439.36

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Solution

The fourth proportional to 646.72, 891.12 and 439.36 is: 605.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.72 : 891.12 = 439.36 : x
  2. Step 2: Convert to fraction form
    646.72/891.12 = 439.36/x
  3. Step 3: Cross multiply
    646.72x = 891.12 × 439.36
  4. Step 4: Simplify right side
    646.72x = 391,522.48
  5. Step 5: Solve for x
    x = 391,522.48/646.72
  6. Step 6: Final answer
    x = 605.40

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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.