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Finding the Fourth Proportional to 451.71, 621.86 and 390.38

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Solution

The fourth proportional to 451.71, 621.86 and 390.38 is: 537.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    451.71 : 621.86 = 390.38 : x
  2. Step 2: Convert to fraction form
    451.71/621.86 = 390.38/x
  3. Step 3: Cross multiply
    451.71x = 621.86 × 390.38
  4. Step 4: Simplify right side
    451.71x = 242,756.65
  5. Step 5: Solve for x
    x = 242,756.65/451.71
  6. Step 6: Final answer
    x = 537.42

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.