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Finding the Fourth Proportional to 642.01, 885.51 and 421.13

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Solution

The fourth proportional to 642.01, 885.51 and 421.13 is: 580.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.01 : 885.51 = 421.13 : x
  2. Step 2: Convert to fraction form
    642.01/885.51 = 421.13/x
  3. Step 3: Cross multiply
    642.01x = 885.51 × 421.13
  4. Step 4: Simplify right side
    642.01x = 372,912.72
  5. Step 5: Solve for x
    x = 372,912.72/642.01
  6. Step 6: Final answer
    x = 580.85

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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.