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Finding the Fourth Proportional to 672.78, 1,009.29 and 288.30

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Solution

The fourth proportional to 672.78, 1,009.29 and 288.30 is: 432.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    672.78 : 1,009.29 = 288.30 : x
  2. Step 2: Convert to fraction form
    672.78/1,009.29 = 288.30/x
  3. Step 3: Cross multiply
    672.78x = 1,009.29 × 288.30
  4. Step 4: Simplify right side
    672.78x = 290,978.31
  5. Step 5: Solve for x
    x = 290,978.31/672.78
  6. Step 6: Final answer
    x = 432.50

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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.