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Finding the Fourth Proportional to 505.80, 698.10 and 309.39

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Solution

The fourth proportional to 505.80, 698.10 and 309.39 is: 427.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    505.80 : 698.10 = 309.39 : x
  2. Step 2: Convert to fraction form
    505.80/698.10 = 309.39/x
  3. Step 3: Cross multiply
    505.80x = 698.10 × 309.39
  4. Step 4: Simplify right side
    505.80x = 215,985.16
  5. Step 5: Solve for x
    x = 215,985.16/505.80
  6. Step 6: Final answer
    x = 427.02

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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.