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Finding the Fourth Proportional to 661.26, 991.08 and 417.72

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Solution

The fourth proportional to 661.26, 991.08 and 417.72 is: 626.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.26 : 991.08 = 417.72 : x
  2. Step 2: Convert to fraction form
    661.26/991.08 = 417.72/x
  3. Step 3: Cross multiply
    661.26x = 991.08 × 417.72
  4. Step 4: Simplify right side
    661.26x = 413,993.94
  5. Step 5: Solve for x
    x = 413,993.94/661.26
  6. Step 6: Final answer
    x = 626.07

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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.