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Finding the Fourth Proportional to 665.70, 918.78 and 417.12

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Solution

The fourth proportional to 665.70, 918.78 and 417.12 is: 575.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.70 : 918.78 = 417.12 : x
  2. Step 2: Convert to fraction form
    665.70/918.78 = 417.12/x
  3. Step 3: Cross multiply
    665.70x = 918.78 × 417.12
  4. Step 4: Simplify right side
    665.70x = 383,241.51
  5. Step 5: Solve for x
    x = 383,241.51/665.70
  6. Step 6: Final answer
    x = 575.70

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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.