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Finding the Fourth Proportional to 665.76, 918.40 and 458.72

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Solution

The fourth proportional to 665.76, 918.40 and 458.72 is: 632.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.76 : 918.40 = 458.72 : x
  2. Step 2: Convert to fraction form
    665.76/918.40 = 458.72/x
  3. Step 3: Cross multiply
    665.76x = 918.40 × 458.72
  4. Step 4: Simplify right side
    665.76x = 421,288.45
  5. Step 5: Solve for x
    x = 421,288.45/665.76
  6. Step 6: Final answer
    x = 632.79

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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.