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Finding the Fourth Proportional to 784.80, 1,082.70 and 469.80

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Solution

The fourth proportional to 784.80, 1,082.70 and 469.80 is: 648.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    784.80 : 1,082.70 = 469.80 : x
  2. Step 2: Convert to fraction form
    784.80/1,082.70 = 469.80/x
  3. Step 3: Cross multiply
    784.80x = 1,082.70 × 469.80
  4. Step 4: Simplify right side
    784.80x = 508,652.46
  5. Step 5: Solve for x
    x = 508,652.46/784.80
  6. Step 6: Final answer
    x = 648.13

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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.