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Finding the Fourth Proportional to 639.75, 882.86 and 407.19

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Solution

The fourth proportional to 639.75, 882.86 and 407.19 is: 561.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.75 : 882.86 = 407.19 : x
  2. Step 2: Convert to fraction form
    639.75/882.86 = 407.19/x
  3. Step 3: Cross multiply
    639.75x = 882.86 × 407.19
  4. Step 4: Simplify right side
    639.75x = 359,489.73
  5. Step 5: Solve for x
    x = 359,489.73/639.75
  6. Step 6: Final answer
    x = 561.92

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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.