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Finding the Fourth Proportional to 714.79, 986.43 and 420.07

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Solution

The fourth proportional to 714.79, 986.43 and 420.07 is: 579.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    714.79 : 986.43 = 420.07 : x
  2. Step 2: Convert to fraction form
    714.79/986.43 = 420.07/x
  3. Step 3: Cross multiply
    714.79x = 986.43 × 420.07
  4. Step 4: Simplify right side
    714.79x = 414,369.65
  5. Step 5: Solve for x
    x = 414,369.65/714.79
  6. Step 6: Final answer
    x = 579.71

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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.