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Finding the Fourth Proportional to 390.36, 585.54 and 219.16

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Solution

The fourth proportional to 390.36, 585.54 and 219.16 is: 328.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.36 : 585.54 = 219.16 : x
  2. Step 2: Convert to fraction form
    390.36/585.54 = 219.16/x
  3. Step 3: Cross multiply
    390.36x = 585.54 × 219.16
  4. Step 4: Simplify right side
    390.36x = 128,326.95
  5. Step 5: Solve for x
    x = 128,326.95/390.36
  6. Step 6: Final answer
    x = 328.74

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.