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Finding the Fourth Proportional to 775.68, 1,069.89 and 480.78

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Solution

The fourth proportional to 775.68, 1,069.89 and 480.78 is: 663.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    775.68 : 1,069.89 = 480.78 : x
  2. Step 2: Convert to fraction form
    775.68/1,069.89 = 480.78/x
  3. Step 3: Cross multiply
    775.68x = 1,069.89 × 480.78
  4. Step 4: Simplify right side
    775.68x = 514,381.71
  5. Step 5: Solve for x
    x = 514,381.71/775.68
  6. Step 6: Final answer
    x = 663.14

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1.5x scale

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.