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Finding the Fourth Proportional to 285.07, 427.34 and 138.74

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Solution

The fourth proportional to 285.07, 427.34 and 138.74 is: 207.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.07 : 427.34 = 138.74 : x
  2. Step 2: Convert to fraction form
    285.07/427.34 = 138.74/x
  3. Step 3: Cross multiply
    285.07x = 427.34 × 138.74
  4. Step 4: Simplify right side
    285.07x = 59,287.01
  5. Step 5: Solve for x
    x = 59,287.01/285.07
  6. Step 6: Final answer
    x = 207.98

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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.