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Finding the Fourth Proportional to 645.87, 891.27 and 380.28

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Solution

The fourth proportional to 645.87, 891.27 and 380.28 is: 524.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.87 : 891.27 = 380.28 : x
  2. Step 2: Convert to fraction form
    645.87/891.27 = 380.28/x
  3. Step 3: Cross multiply
    645.87x = 891.27 × 380.28
  4. Step 4: Simplify right side
    645.87x = 338,932.16
  5. Step 5: Solve for x
    x = 338,932.16/645.87
  6. Step 6: Final answer
    x = 524.77

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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.