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Finding the Fourth Proportional to 521.59, 780.96 and 399.28

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Solution

The fourth proportional to 521.59, 780.96 and 399.28 is: 597.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.59 : 780.96 = 399.28 : x
  2. Step 2: Convert to fraction form
    521.59/780.96 = 399.28/x
  3. Step 3: Cross multiply
    521.59x = 780.96 × 399.28
  4. Step 4: Simplify right side
    521.59x = 311,815.81
  5. Step 5: Solve for x
    x = 311,815.81/521.59
  6. Step 6: Final answer
    x = 597.82

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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.