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Finding the Fourth Proportional to 279.90, 392.40 and 279.90

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Solution

The fourth proportional to 279.90, 392.40 and 279.90 is: 392.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.90 : 392.40 = 279.90 : x
  2. Step 2: Convert to fraction form
    279.90/392.40 = 279.90/x
  3. Step 3: Cross multiply
    279.90x = 392.40 × 279.90
  4. Step 4: Simplify right side
    279.90x = 109,832.76
  5. Step 5: Solve for x
    x = 109,832.76/279.90
  6. Step 6: Final answer
    x = 392.40

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Why These Related Problems?

These problems maintain the same ratio (1.40) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.