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Finding the Fourth Proportional to 642.29, 886.75 and 421.63

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Solution

The fourth proportional to 642.29, 886.75 and 421.63 is: 582.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.29 : 886.75 = 421.63 : x
  2. Step 2: Convert to fraction form
    642.29/886.75 = 421.63/x
  3. Step 3: Cross multiply
    642.29x = 886.75 × 421.63
  4. Step 4: Simplify right side
    642.29x = 373,878.29
  5. Step 5: Solve for x
    x = 373,878.29/642.29
  6. Step 6: Final answer
    x = 582.10

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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.