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Finding the Fourth Proportional to 521.64, 780.48 and 430.56

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Solution

The fourth proportional to 521.64, 780.48 and 430.56 is: 644.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.64 : 780.48 = 430.56 : x
  2. Step 2: Convert to fraction form
    521.64/780.48 = 430.56/x
  3. Step 3: Cross multiply
    521.64x = 780.48 × 430.56
  4. Step 4: Simplify right side
    521.64x = 336,043.47
  5. Step 5: Solve for x
    x = 336,043.47/521.64
  6. Step 6: Final answer
    x = 644.21

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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.