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Finding the Fourth Proportional to 665.75, 918.71 and 417.20

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Solution

The fourth proportional to 665.75, 918.71 and 417.20 is: 575.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.75 : 918.71 = 417.20 : x
  2. Step 2: Convert to fraction form
    665.75/918.71 = 417.20/x
  3. Step 3: Cross multiply
    665.75x = 918.71 × 417.20
  4. Step 4: Simplify right side
    665.75x = 383,284.33
  5. Step 5: Solve for x
    x = 383,284.33/665.75
  6. Step 6: Final answer
    x = 575.72

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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.