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Finding the Fourth Proportional to 872.90, 1,308.63 and 324.78

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Solution

The fourth proportional to 872.90, 1,308.63 and 324.78 is: 486.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    872.90 : 1,308.63 = 324.78 : x
  2. Step 2: Convert to fraction form
    872.90/1,308.63 = 324.78/x
  3. Step 3: Cross multiply
    872.90x = 1,308.63 × 324.78
  4. Step 4: Simplify right side
    872.90x = 425,023.29
  5. Step 5: Solve for x
    x = 425,023.29/872.90
  6. Step 6: Final answer
    x = 486.91

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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.