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Finding the Fourth Proportional to 659.94, 988.62 and 312.78

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Solution

The fourth proportional to 659.94, 988.62 and 312.78 is: 468.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.94 : 988.62 = 312.78 : x
  2. Step 2: Convert to fraction form
    659.94/988.62 = 312.78/x
  3. Step 3: Cross multiply
    659.94x = 988.62 × 312.78
  4. Step 4: Simplify right side
    659.94x = 309,220.56
  5. Step 5: Solve for x
    x = 309,220.56/659.94
  6. Step 6: Final answer
    x = 468.56

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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.