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Finding the Fourth Proportional to 642.65, 961.94 and 447.08

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Solution

The fourth proportional to 642.65, 961.94 and 447.08 is: 669.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.65 : 961.94 = 447.08 : x
  2. Step 2: Convert to fraction form
    642.65/961.94 = 447.08/x
  3. Step 3: Cross multiply
    642.65x = 961.94 × 447.08
  4. Step 4: Simplify right side
    642.65x = 430,060.44
  5. Step 5: Solve for x
    x = 430,060.44/642.65
  6. Step 6: Final answer
    x = 669.20

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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.