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Finding the Fourth Proportional to 665.40, 917.28 and 499.62

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Solution

The fourth proportional to 665.40, 917.28 and 499.62 is: 688.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.40 : 917.28 = 499.62 : x
  2. Step 2: Convert to fraction form
    665.40/917.28 = 499.62/x
  3. Step 3: Cross multiply
    665.40x = 917.28 × 499.62
  4. Step 4: Simplify right side
    665.40x = 458,291.43
  5. Step 5: Solve for x
    x = 458,291.43/665.40
  6. Step 6: Final answer
    x = 688.75

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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.