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Finding the Fourth Proportional to 642.84, 886.30 and 421.44

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Solution

The fourth proportional to 642.84, 886.30 and 421.44 is: 581.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.84 : 886.30 = 421.44 : x
  2. Step 2: Convert to fraction form
    642.84/886.30 = 421.44/x
  3. Step 3: Cross multiply
    642.84x = 886.30 × 421.44
  4. Step 4: Simplify right side
    642.84x = 373,522.27
  5. Step 5: Solve for x
    x = 373,522.27/642.84
  6. Step 6: Final answer
    x = 581.05

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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.