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Finding the Fourth Proportional to 659.91, 990.21 and 386.53

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Solution

The fourth proportional to 659.91, 990.21 and 386.53 is: 580.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.91 : 990.21 = 386.53 : x
  2. Step 2: Convert to fraction form
    659.91/990.21 = 386.53/x
  3. Step 3: Cross multiply
    659.91x = 990.21 × 386.53
  4. Step 4: Simplify right side
    659.91x = 382,745.87
  5. Step 5: Solve for x
    x = 382,745.87/659.91
  6. Step 6: Final answer
    x = 580.00

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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.