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Finding the Fourth Proportional to 642.38, 886.28 and 455.72

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Solution

The fourth proportional to 642.38, 886.28 and 455.72 is: 628.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.38 : 886.28 = 455.72 : x
  2. Step 2: Convert to fraction form
    642.38/886.28 = 455.72/x
  3. Step 3: Cross multiply
    642.38x = 886.28 × 455.72
  4. Step 4: Simplify right side
    642.38x = 403,895.52
  5. Step 5: Solve for x
    x = 403,895.52/642.38
  6. Step 6: Final answer
    x = 628.75

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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.