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Finding the Fourth Proportional to 642.17, 961.40 and 446.70

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Solution

The fourth proportional to 642.17, 961.40 and 446.70 is: 668.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.17 : 961.40 = 446.70 : x
  2. Step 2: Convert to fraction form
    642.17/961.40 = 446.70/x
  3. Step 3: Cross multiply
    642.17x = 961.40 × 446.70
  4. Step 4: Simplify right side
    642.17x = 429,457.38
  5. Step 5: Solve for x
    x = 429,457.38/642.17
  6. Step 6: Final answer
    x = 668.76

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.