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Finding the Fourth Proportional to 872.31, 1,308.19 and 287.18

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Solution

The fourth proportional to 872.31, 1,308.19 and 287.18 is: 430.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    872.31 : 1,308.19 = 287.18 : x
  2. Step 2: Convert to fraction form
    872.31/1,308.19 = 287.18/x
  3. Step 3: Cross multiply
    872.31x = 1,308.19 × 287.18
  4. Step 4: Simplify right side
    872.31x = 375,683.79
  5. Step 5: Solve for x
    x = 375,683.79/872.31
  6. Step 6: Final answer
    x = 430.68

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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.