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Finding the Fourth Proportional to 558.19, 770.61 and 390.39

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Solution

The fourth proportional to 558.19, 770.61 and 390.39 is: 538.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    558.19 : 770.61 = 390.39 : x
  2. Step 2: Convert to fraction form
    558.19/770.61 = 390.39/x
  3. Step 3: Cross multiply
    558.19x = 770.61 × 390.39
  4. Step 4: Simplify right side
    558.19x = 300,834.58
  5. Step 5: Solve for x
    x = 300,834.58/558.19
  6. Step 6: Final answer
    x = 538.95

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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.