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Finding the Fourth Proportional to 860.60, 1,289.88 and 312.36

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Solution

The fourth proportional to 860.60, 1,289.88 and 312.36 is: 468.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.60 : 1,289.88 = 312.36 : x
  2. Step 2: Convert to fraction form
    860.60/1,289.88 = 312.36/x
  3. Step 3: Cross multiply
    860.60x = 1,289.88 × 312.36
  4. Step 4: Simplify right side
    860.60x = 402,906.92
  5. Step 5: Solve for x
    x = 402,906.92/860.60
  6. Step 6: Final answer
    x = 468.17

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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.