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Finding the Fourth Proportional to 775.81, 1,070.79 and 480.90

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Solution

The fourth proportional to 775.81, 1,070.79 and 480.90 is: 663.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    775.81 : 1,070.79 = 480.90 : x
  2. Step 2: Convert to fraction form
    775.81/1,070.79 = 480.90/x
  3. Step 3: Cross multiply
    775.81x = 1,070.79 × 480.90
  4. Step 4: Simplify right side
    775.81x = 514,945.12
  5. Step 5: Solve for x
    x = 514,945.12/775.81
  6. Step 6: Final answer
    x = 663.75

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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.