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Finding the Fourth Proportional to 621.45, 931.14 and 438.53

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Solution

The fourth proportional to 621.45, 931.14 and 438.53 is: 657.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.45 : 931.14 = 438.53 : x
  2. Step 2: Convert to fraction form
    621.45/931.14 = 438.53/x
  3. Step 3: Cross multiply
    621.45x = 931.14 × 438.53
  4. Step 4: Simplify right side
    621.45x = 408,328.17
  5. Step 5: Solve for x
    x = 408,328.17/621.45
  6. Step 6: Final answer
    x = 657.06

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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.