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Finding the Fourth Proportional to 1,005.85, 1,508.37 and 420.45

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Solution

The fourth proportional to 1,005.85, 1,508.37 and 420.45 is: 630.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,005.85 : 1,508.37 = 420.45 : x
  2. Step 2: Convert to fraction form
    1,005.85/1,508.37 = 420.45/x
  3. Step 3: Cross multiply
    1,005.85x = 1,508.37 × 420.45
  4. Step 4: Simplify right side
    1,005.85x = 634,194.17
  5. Step 5: Solve for x
    x = 634,194.17/1,005.85
  6. Step 6: Final answer
    x = 630.51

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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.