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Finding the Fourth Proportional to 505.96, 698.40 and 309.40

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Solution

The fourth proportional to 505.96, 698.40 and 309.40 is: 427.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    505.96 : 698.40 = 309.40 : x
  2. Step 2: Convert to fraction form
    505.96/698.40 = 309.40/x
  3. Step 3: Cross multiply
    505.96x = 698.40 × 309.40
  4. Step 4: Simplify right side
    505.96x = 216,084.96
  5. Step 5: Solve for x
    x = 216,084.96/505.96
  6. Step 6: Final answer
    x = 427.08

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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.