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Finding the Fourth Proportional to 661.52, 991.59 and 430.57

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Solution

The fourth proportional to 661.52, 991.59 and 430.57 is: 645.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.52 : 991.59 = 430.57 : x
  2. Step 2: Convert to fraction form
    661.52/991.59 = 430.57/x
  3. Step 3: Cross multiply
    661.52x = 991.59 × 430.57
  4. Step 4: Simplify right side
    661.52x = 426,948.91
  5. Step 5: Solve for x
    x = 426,948.91/661.52
  6. Step 6: Final answer
    x = 645.41

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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.