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Finding the Fourth Proportional to 762.80, 1,142.40 and 471.20

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Solution

The fourth proportional to 762.80, 1,142.40 and 471.20 is: 705.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    762.80 : 1,142.40 = 471.20 : x
  2. Step 2: Convert to fraction form
    762.80/1,142.40 = 471.20/x
  3. Step 3: Cross multiply
    762.80x = 1,142.40 × 471.20
  4. Step 4: Simplify right side
    762.80x = 538,298.88
  5. Step 5: Solve for x
    x = 538,298.88/762.80
  6. Step 6: Final answer
    x = 705.69

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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.