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Finding the Fourth Proportional to 659.36, 988.80 and 398.72

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Solution

The fourth proportional to 659.36, 988.80 and 398.72 is: 597.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.36 : 988.80 = 398.72 : x
  2. Step 2: Convert to fraction form
    659.36/988.80 = 398.72/x
  3. Step 3: Cross multiply
    659.36x = 988.80 × 398.72
  4. Step 4: Simplify right side
    659.36x = 394,254.34
  5. Step 5: Solve for x
    x = 394,254.34/659.36
  6. Step 6: Final answer
    x = 597.93

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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.