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Finding the Fourth Proportional to 387.15, 578.54 and 279.15

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Solution

The fourth proportional to 387.15, 578.54 and 279.15 is: 417.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.15 : 578.54 = 279.15 : x
  2. Step 2: Convert to fraction form
    387.15/578.54 = 279.15/x
  3. Step 3: Cross multiply
    387.15x = 578.54 × 279.15
  4. Step 4: Simplify right side
    387.15x = 161,498.05
  5. Step 5: Solve for x
    x = 161,498.05/387.15
  6. Step 6: Final answer
    x = 417.15

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.