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Finding the Fourth Proportional to 491.85, 679.47 and 393.48

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Solution

The fourth proportional to 491.85, 679.47 and 393.48 is: 543.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.85 : 679.47 = 393.48 : x
  2. Step 2: Convert to fraction form
    491.85/679.47 = 393.48/x
  3. Step 3: Cross multiply
    491.85x = 679.47 × 393.48
  4. Step 4: Simplify right side
    491.85x = 267,357.86
  5. Step 5: Solve for x
    x = 267,357.86/491.85
  6. Step 6: Final answer
    x = 543.58

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.