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Finding the Fourth Proportional to 642.89, 886.90 and 406.77

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Solution

The fourth proportional to 642.89, 886.90 and 406.77 is: 561.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.89 : 886.90 = 406.77 : x
  2. Step 2: Convert to fraction form
    642.89/886.90 = 406.77/x
  3. Step 3: Cross multiply
    642.89x = 886.90 × 406.77
  4. Step 4: Simplify right side
    642.89x = 360,765.72
  5. Step 5: Solve for x
    x = 360,765.72/642.89
  6. Step 6: Final answer
    x = 561.17

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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.