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Finding the Fourth Proportional to 309.66, 426.48 and 288.36

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Solution

The fourth proportional to 309.66, 426.48 and 288.36 is: 397.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.66 : 426.48 = 288.36 : x
  2. Step 2: Convert to fraction form
    309.66/426.48 = 288.36/x
  3. Step 3: Cross multiply
    309.66x = 426.48 × 288.36
  4. Step 4: Simplify right side
    309.66x = 122,979.77
  5. Step 5: Solve for x
    x = 122,979.77/309.66
  6. Step 6: Final answer
    x = 397.14

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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.