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Finding the Fourth Proportional to 285.18, 427.58 and 138.77

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Solution

The fourth proportional to 285.18, 427.58 and 138.77 is: 208.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.18 : 427.58 = 138.77 : x
  2. Step 2: Convert to fraction form
    285.18/427.58 = 138.77/x
  3. Step 3: Cross multiply
    285.18x = 427.58 × 138.77
  4. Step 4: Simplify right side
    285.18x = 59,332.44
  5. Step 5: Solve for x
    x = 59,332.44/285.18
  6. Step 6: Final answer
    x = 208.05

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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.