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Finding the Fourth Proportional to 642.84, 887.12 and 394.14

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Solution

The fourth proportional to 642.84, 887.12 and 394.14 is: 543.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.84 : 887.12 = 394.14 : x
  2. Step 2: Convert to fraction form
    642.84/887.12 = 394.14/x
  3. Step 3: Cross multiply
    642.84x = 887.12 × 394.14
  4. Step 4: Simplify right side
    642.84x = 349,649.48
  5. Step 5: Solve for x
    x = 349,649.48/642.84
  6. Step 6: Final answer
    x = 543.91

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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.