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Finding the Fourth Proportional to 639.34, 882.69 and 499.21

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Solution

The fourth proportional to 639.34, 882.69 and 499.21 is: 689.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.34 : 882.69 = 499.21 : x
  2. Step 2: Convert to fraction form
    639.34/882.69 = 499.21/x
  3. Step 3: Cross multiply
    639.34x = 882.69 × 499.21
  4. Step 4: Simplify right side
    639.34x = 440,643.26
  5. Step 5: Solve for x
    x = 440,643.26/639.34
  6. Step 6: Final answer
    x = 689.22

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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.