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Finding the Fourth Proportional to 642.52, 886.92 and 421.66

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Solution

The fourth proportional to 642.52, 886.92 and 421.66 is: 582.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.52 : 886.92 = 421.66 : x
  2. Step 2: Convert to fraction form
    642.52/886.92 = 421.66/x
  3. Step 3: Cross multiply
    642.52x = 886.92 × 421.66
  4. Step 4: Simplify right side
    642.52x = 373,978.69
  5. Step 5: Solve for x
    x = 373,978.69/642.52
  6. Step 6: Final answer
    x = 582.05

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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.