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Finding the Fourth Proportional to 518.84, 780.87 and 389.53

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Solution

The fourth proportional to 518.84, 780.87 and 389.53 is: 586.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.84 : 780.87 = 389.53 : x
  2. Step 2: Convert to fraction form
    518.84/780.87 = 389.53/x
  3. Step 3: Cross multiply
    518.84x = 780.87 × 389.53
  4. Step 4: Simplify right side
    518.84x = 304,172.29
  5. Step 5: Solve for x
    x = 304,172.29/518.84
  6. Step 6: Final answer
    x = 586.25

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.