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Finding the Fourth Proportional to 555.35, 766.63 and 390.42

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Solution

The fourth proportional to 555.35, 766.63 and 390.42 is: 538.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    555.35 : 766.63 = 390.42 : x
  2. Step 2: Convert to fraction form
    555.35/766.63 = 390.42/x
  3. Step 3: Cross multiply
    555.35x = 766.63 × 390.42
  4. Step 4: Simplify right side
    555.35x = 299,308.17
  5. Step 5: Solve for x
    x = 299,308.17/555.35
  6. Step 6: Final answer
    x = 538.96

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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.