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Finding the Fourth Proportional to 642.34, 886.78 and 421.62

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Solution

The fourth proportional to 642.34, 886.78 and 421.62 is: 582.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.34 : 886.78 = 421.62 : x
  2. Step 2: Convert to fraction form
    642.34/886.78 = 421.62/x
  3. Step 3: Cross multiply
    642.34x = 886.78 × 421.62
  4. Step 4: Simplify right side
    642.34x = 373,884.18
  5. Step 5: Solve for x
    x = 373,884.18/642.34
  6. Step 6: Final answer
    x = 582.07

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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.