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Finding the Fourth Proportional to 356.78, 492.30 and 209.40

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Solution

The fourth proportional to 356.78, 492.30 and 209.40 is: 288.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    356.78 : 492.30 = 209.40 : x
  2. Step 2: Convert to fraction form
    356.78/492.30 = 209.40/x
  3. Step 3: Cross multiply
    356.78x = 492.30 × 209.40
  4. Step 4: Simplify right side
    356.78x = 103,087.62
  5. Step 5: Solve for x
    x = 103,087.62/356.78
  6. Step 6: Final answer
    x = 288.94

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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.