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Finding the Fourth Proportional to 390.34, 585.48 and 101.78

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Solution

The fourth proportional to 390.34, 585.48 and 101.78 is: 152.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.34 : 585.48 = 101.78 : x
  2. Step 2: Convert to fraction form
    390.34/585.48 = 101.78/x
  3. Step 3: Cross multiply
    390.34x = 585.48 × 101.78
  4. Step 4: Simplify right side
    390.34x = 59,589.65
  5. Step 5: Solve for x
    x = 59,589.65/390.34
  6. Step 6: Final answer
    x = 152.66

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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.