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Finding the Fourth Proportional to 665.26, 998.70 and 391.48

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Solution

The fourth proportional to 665.26, 998.70 and 391.48 is: 587.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.26 : 998.70 = 391.48 : x
  2. Step 2: Convert to fraction form
    665.26/998.70 = 391.48/x
  3. Step 3: Cross multiply
    665.26x = 998.70 × 391.48
  4. Step 4: Simplify right side
    665.26x = 390,971.08
  5. Step 5: Solve for x
    x = 390,971.08/665.26
  6. Step 6: Final answer
    x = 587.70

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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.