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Finding the Fourth Proportional to 765.70, 1,148.55 and 278.70

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Solution

The fourth proportional to 765.70, 1,148.55 and 278.70 is: 418.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    765.70 : 1,148.55 = 278.70 : x
  2. Step 2: Convert to fraction form
    765.70/1,148.55 = 278.70/x
  3. Step 3: Cross multiply
    765.70x = 1,148.55 × 278.70
  4. Step 4: Simplify right side
    765.70x = 320,100.89
  5. Step 5: Solve for x
    x = 320,100.89/765.70
  6. Step 6: Final answer
    x = 418.05

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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.