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Finding the Fourth Proportional to 431.40, 647.02 and 123.18

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Solution

The fourth proportional to 431.40, 647.02 and 123.18 is: 184.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.40 : 647.02 = 123.18 : x
  2. Step 2: Convert to fraction form
    431.40/647.02 = 123.18/x
  3. Step 3: Cross multiply
    431.40x = 647.02 × 123.18
  4. Step 4: Simplify right side
    431.40x = 79,699.92
  5. Step 5: Solve for x
    x = 79,699.92/431.40
  6. Step 6: Final answer
    x = 184.75

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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.