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Finding the Fourth Proportional to 1,006.20, 1,507.68 and 420.71

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Solution

The fourth proportional to 1,006.20, 1,507.68 and 420.71 is: 630.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,006.20 : 1,507.68 = 420.71 : x
  2. Step 2: Convert to fraction form
    1,006.20/1,507.68 = 420.71/x
  3. Step 3: Cross multiply
    1,006.20x = 1,507.68 × 420.71
  4. Step 4: Simplify right side
    1,006.20x = 634,288.51
  5. Step 5: Solve for x
    x = 634,288.51/1,006.20
  6. Step 6: Final answer
    x = 630.38

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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.