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Finding the Fourth Proportional to 665.45, 917.23 and 478.64

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Solution

The fourth proportional to 665.45, 917.23 and 478.64 is: 659.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.45 : 917.23 = 478.64 : x
  2. Step 2: Convert to fraction form
    665.45/917.23 = 478.64/x
  3. Step 3: Cross multiply
    665.45x = 917.23 × 478.64
  4. Step 4: Simplify right side
    665.45x = 439,022.97
  5. Step 5: Solve for x
    x = 439,022.97/665.45
  6. Step 6: Final answer
    x = 659.74

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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.