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Finding the Fourth Proportional to 390.48, 539.07 and 258.08

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Solution

The fourth proportional to 390.48, 539.07 and 258.08 is: 356.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.48 : 539.07 = 258.08 : x
  2. Step 2: Convert to fraction form
    390.48/539.07 = 258.08/x
  3. Step 3: Cross multiply
    390.48x = 539.07 × 258.08
  4. Step 4: Simplify right side
    390.48x = 139,120.49
  5. Step 5: Solve for x
    x = 139,120.49/390.48
  6. Step 6: Final answer
    x = 356.28

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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.