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Finding the Fourth Proportional to 621.28, 931.38 and 429.04

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Solution

The fourth proportional to 621.28, 931.38 and 429.04 is: 643.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.28 : 931.38 = 429.04 : x
  2. Step 2: Convert to fraction form
    621.28/931.38 = 429.04/x
  3. Step 3: Cross multiply
    621.28x = 931.38 × 429.04
  4. Step 4: Simplify right side
    621.28x = 399,599.28
  5. Step 5: Solve for x
    x = 399,599.28/621.28
  6. Step 6: Final answer
    x = 643.19

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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.