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Finding the Fourth Proportional to 679.78, 936.43 and 492.72

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Solution

The fourth proportional to 679.78, 936.43 and 492.72 is: 678.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.78 : 936.43 = 492.72 : x
  2. Step 2: Convert to fraction form
    679.78/936.43 = 492.72/x
  3. Step 3: Cross multiply
    679.78x = 936.43 × 492.72
  4. Step 4: Simplify right side
    679.78x = 461,397.79
  5. Step 5: Solve for x
    x = 461,397.79/679.78
  6. Step 6: Final answer
    x = 678.75

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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.