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Finding the Fourth Proportional to 1,288.70, 1,933.07 and 423

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Solution

The fourth proportional to 1,288.70, 1,933.07 and 423 is: 634.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,288.70 : 1,933.07 = 423 : x
  2. Step 2: Convert to fraction form
    1,288.70/1,933.07 = 423/x
  3. Step 3: Cross multiply
    1,288.70x = 1,933.07 × 423
  4. Step 4: Simplify right side
    1,288.70x = 817,686.50
  5. Step 5: Solve for x
    x = 817,686.50/1,288.70
  6. Step 6: Final answer
    x = 634.51

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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.