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Finding the Fourth Proportional to 1,288.23, 1,932.35 and 639.42

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Solution

The fourth proportional to 1,288.23, 1,932.35 and 639.42 is: 959.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,288.23 : 1,932.35 = 639.42 : x
  2. Step 2: Convert to fraction form
    1,288.23/1,932.35 = 639.42/x
  3. Step 3: Cross multiply
    1,288.23x = 1,932.35 × 639.42
  4. Step 4: Simplify right side
    1,288.23x = 1,235,580.04
  5. Step 5: Solve for x
    x = 1,235,580.04/1,288.23
  6. Step 6: Final answer
    x = 959.13

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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.