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Finding the Fourth Proportional to 343.90, 515.70 and 278.68

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Solution

The fourth proportional to 343.90, 515.70 and 278.68 is: 417.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    343.90 : 515.70 = 278.68 : x
  2. Step 2: Convert to fraction form
    343.90/515.70 = 278.68/x
  3. Step 3: Cross multiply
    343.90x = 515.70 × 278.68
  4. Step 4: Simplify right side
    343.90x = 143,715.28
  5. Step 5: Solve for x
    x = 143,715.28/343.90
  6. Step 6: Final answer
    x = 417.90

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.