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Finding the Fourth Proportional to 521.45, 780.56 and 447.64

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Solution

The fourth proportional to 521.45, 780.56 and 447.64 is: 670.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.45 : 780.56 = 447.64 : x
  2. Step 2: Convert to fraction form
    521.45/780.56 = 447.64/x
  3. Step 3: Cross multiply
    521.45x = 780.56 × 447.64
  4. Step 4: Simplify right side
    521.45x = 349,409.05
  5. Step 5: Solve for x
    x = 349,409.05/521.45
  6. Step 6: Final answer
    x = 670.08

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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.