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Finding the Fourth Proportional to 659.88, 989.80 and 386.08

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Solution

The fourth proportional to 659.88, 989.80 and 386.08 is: 579.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.88 : 989.80 = 386.08 : x
  2. Step 2: Convert to fraction form
    659.88/989.80 = 386.08/x
  3. Step 3: Cross multiply
    659.88x = 989.80 × 386.08
  4. Step 4: Simplify right side
    659.88x = 382,141.98
  5. Step 5: Solve for x
    x = 382,141.98/659.88
  6. Step 6: Final answer
    x = 579.11

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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.