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Finding the Fourth Proportional to 555.45, 766.61 and 389.91

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Solution

The fourth proportional to 555.45, 766.61 and 389.91 is: 538.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    555.45 : 766.61 = 389.91 : x
  2. Step 2: Convert to fraction form
    555.45/766.61 = 389.91/x
  3. Step 3: Cross multiply
    555.45x = 766.61 × 389.91
  4. Step 4: Simplify right side
    555.45x = 298,908.91
  5. Step 5: Solve for x
    x = 298,908.91/555.45
  6. Step 6: Final answer
    x = 538.14

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.