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Finding the Fourth Proportional to 764.20, 1,139.09 and 692.20

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Solution

The fourth proportional to 764.20, 1,139.09 and 692.20 is: 1,031.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    764.20 : 1,139.09 = 692.20 : x
  2. Step 2: Convert to fraction form
    764.20/1,139.09 = 692.20/x
  3. Step 3: Cross multiply
    764.20x = 1,139.09 × 692.20
  4. Step 4: Simplify right side
    764.20x = 788,478.10
  5. Step 5: Solve for x
    x = 788,478.10/764.20
  6. Step 6: Final answer
    x = 1,031.77

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.