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Finding the Fourth Proportional to 140.31, 210.29 and 78.53

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Solution

The fourth proportional to 140.31, 210.29 and 78.53 is: 117.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    140.31 : 210.29 = 78.53 : x
  2. Step 2: Convert to fraction form
    140.31/210.29 = 78.53/x
  3. Step 3: Cross multiply
    140.31x = 210.29 × 78.53
  4. Step 4: Simplify right side
    140.31x = 16,512.63
  5. Step 5: Solve for x
    x = 16,512.63/140.31
  6. Step 6: Final answer
    x = 117.69

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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.