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Finding the Fourth Proportional to 1,259.60, 1,887.76 and 642.76

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Solution

The fourth proportional to 1,259.60, 1,887.76 and 642.76 is: 963.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,259.60 : 1,887.76 = 642.76 : x
  2. Step 2: Convert to fraction form
    1,259.60/1,887.76 = 642.76/x
  3. Step 3: Cross multiply
    1,259.60x = 1,887.76 × 642.76
  4. Step 4: Simplify right side
    1,259.60x = 1,213,376.62
  5. Step 5: Solve for x
    x = 1,213,376.62/1,259.60
  6. Step 6: Final answer
    x = 963.30

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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.