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Finding the Fourth Proportional to 918.12, 1,377.16 and 430.90

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Solution

The fourth proportional to 918.12, 1,377.16 and 430.90 is: 646.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    918.12 : 1,377.16 = 430.90 : x
  2. Step 2: Convert to fraction form
    918.12/1,377.16 = 430.90/x
  3. Step 3: Cross multiply
    918.12x = 1,377.16 × 430.90
  4. Step 4: Simplify right side
    918.12x = 593,418.24
  5. Step 5: Solve for x
    x = 593,418.24/918.12
  6. Step 6: Final answer
    x = 646.34

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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.