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Finding the Fourth Proportional to 659.68, 990.40 and 415.44

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Solution

The fourth proportional to 659.68, 990.40 and 415.44 is: 623.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.68 : 990.40 = 415.44 : x
  2. Step 2: Convert to fraction form
    659.68/990.40 = 415.44/x
  3. Step 3: Cross multiply
    659.68x = 990.40 × 415.44
  4. Step 4: Simplify right side
    659.68x = 411,451.78
  5. Step 5: Solve for x
    x = 411,451.78/659.68
  6. Step 6: Final answer
    x = 623.71

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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.