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Finding the Fourth Proportional to 775.64, 1,070.38 and 421.56

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Solution

The fourth proportional to 775.64, 1,070.38 and 421.56 is: 581.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    775.64 : 1,070.38 = 421.56 : x
  2. Step 2: Convert to fraction form
    775.64/1,070.38 = 421.56/x
  3. Step 3: Cross multiply
    775.64x = 1,070.38 × 421.56
  4. Step 4: Simplify right side
    775.64x = 451,227.69
  5. Step 5: Solve for x
    x = 451,227.69/775.64
  6. Step 6: Final answer
    x = 581.75

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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.