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Finding the Fourth Proportional to 665.38, 917.22 and 478.54

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Solution

The fourth proportional to 665.38, 917.22 and 478.54 is: 659.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.38 : 917.22 = 478.54 : x
  2. Step 2: Convert to fraction form
    665.38/917.22 = 478.54/x
  3. Step 3: Cross multiply
    665.38x = 917.22 × 478.54
  4. Step 4: Simplify right side
    665.38x = 438,926.46
  5. Step 5: Solve for x
    x = 438,926.46/665.38
  6. Step 6: Final answer
    x = 659.66

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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.