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Finding the Fourth Proportional to 285.40, 427.82 and 139.12

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Solution

The fourth proportional to 285.40, 427.82 and 139.12 is: 208.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.40 : 427.82 = 139.12 : x
  2. Step 2: Convert to fraction form
    285.40/427.82 = 139.12/x
  3. Step 3: Cross multiply
    285.40x = 427.82 × 139.12
  4. Step 4: Simplify right side
    285.40x = 59,518.32
  5. Step 5: Solve for x
    x = 59,518.32/285.40
  6. Step 6: Final answer
    x = 208.54

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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.