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Finding the Fourth Proportional to 621.18, 931.32 and 312.81

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Solution

The fourth proportional to 621.18, 931.32 and 312.81 is: 468.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.18 : 931.32 = 312.81 : x
  2. Step 2: Convert to fraction form
    621.18/931.32 = 312.81/x
  3. Step 3: Cross multiply
    621.18x = 931.32 × 312.81
  4. Step 4: Simplify right side
    621.18x = 291,326.21
  5. Step 5: Solve for x
    x = 291,326.21/621.18
  6. Step 6: Final answer
    x = 468.99

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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.