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Finding the Fourth Proportional to 1,289.88, 1,932.93 and 639.32

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Solution

The fourth proportional to 1,289.88, 1,932.93 and 639.32 is: 958.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,289.88 : 1,932.93 = 639.32 : x
  2. Step 2: Convert to fraction form
    1,289.88/1,932.93 = 639.32/x
  3. Step 3: Cross multiply
    1,289.88x = 1,932.93 × 639.32
  4. Step 4: Simplify right side
    1,289.88x = 1,235,751.14
  5. Step 5: Solve for x
    x = 1,235,751.14/1,289.88
  6. Step 6: Final answer
    x = 958.04

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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.