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Finding the Fourth Proportional to 660.90, 991.62 and 417.36

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Solution

The fourth proportional to 660.90, 991.62 and 417.36 is: 626.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.90 : 991.62 = 417.36 : x
  2. Step 2: Convert to fraction form
    660.90/991.62 = 417.36/x
  3. Step 3: Cross multiply
    660.90x = 991.62 × 417.36
  4. Step 4: Simplify right side
    660.90x = 413,862.52
  5. Step 5: Solve for x
    x = 413,862.52/660.90
  6. Step 6: Final answer
    x = 626.21

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.