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Finding the Fourth Proportional to 714.40, 985.70 and 493.80

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Solution

The fourth proportional to 714.40, 985.70 and 493.80 is: 681.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    714.40 : 985.70 = 493.80 : x
  2. Step 2: Convert to fraction form
    714.40/985.70 = 493.80/x
  3. Step 3: Cross multiply
    714.40x = 985.70 × 493.80
  4. Step 4: Simplify right side
    714.40x = 486,738.66
  5. Step 5: Solve for x
    x = 486,738.66/714.40
  6. Step 6: Final answer
    x = 681.33

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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.