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Finding the Fourth Proportional to 521.65, 780.10 and 389.97

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Solution

The fourth proportional to 521.65, 780.10 and 389.97 is: 583.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.65 : 780.10 = 389.97 : x
  2. Step 2: Convert to fraction form
    521.65/780.10 = 389.97/x
  3. Step 3: Cross multiply
    521.65x = 780.10 × 389.97
  4. Step 4: Simplify right side
    521.65x = 304,215.60
  5. Step 5: Solve for x
    x = 304,215.60/521.65
  6. Step 6: Final answer
    x = 583.18

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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.