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Finding the Fourth Proportional to 612.30, 918.88 and 287.70

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Solution

The fourth proportional to 612.30, 918.88 and 287.70 is: 431.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    612.30 : 918.88 = 287.70 : x
  2. Step 2: Convert to fraction form
    612.30/918.88 = 287.70/x
  3. Step 3: Cross multiply
    612.30x = 918.88 × 287.70
  4. Step 4: Simplify right side
    612.30x = 264,361.78
  5. Step 5: Solve for x
    x = 264,361.78/612.30
  6. Step 6: Final answer
    x = 431.75

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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.