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Finding the Fourth Proportional to 319.29, 442.79 and 309.30

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Solution

The fourth proportional to 319.29, 442.79 and 309.30 is: 428.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    319.29 : 442.79 = 309.30 : x
  2. Step 2: Convert to fraction form
    319.29/442.79 = 309.30/x
  3. Step 3: Cross multiply
    319.29x = 442.79 × 309.30
  4. Step 4: Simplify right side
    319.29x = 136,953.40
  5. Step 5: Solve for x
    x = 136,953.40/319.29
  6. Step 6: Final answer
    x = 428.93

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.