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Finding the Fourth Proportional to 285.54, 428.41 and 139.34

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Solution

The fourth proportional to 285.54, 428.41 and 139.34 is: 209.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.54 : 428.41 = 139.34 : x
  2. Step 2: Convert to fraction form
    285.54/428.41 = 139.34/x
  3. Step 3: Cross multiply
    285.54x = 428.41 × 139.34
  4. Step 4: Simplify right side
    285.54x = 59,692.51
  5. Step 5: Solve for x
    x = 59,692.51/285.54
  6. Step 6: Final answer
    x = 209.05

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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.