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Finding the Fourth Proportional to 642.19, 885.18 and 455.68

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Solution

The fourth proportional to 642.19, 885.18 and 455.68 is: 628.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.19 : 885.18 = 455.68 : x
  2. Step 2: Convert to fraction form
    642.19/885.18 = 455.68/x
  3. Step 3: Cross multiply
    642.19x = 885.18 × 455.68
  4. Step 4: Simplify right side
    642.19x = 403,358.82
  5. Step 5: Solve for x
    x = 403,358.82/642.19
  6. Step 6: Final answer
    x = 628.10

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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.