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Finding the Fourth Proportional to 345.68, 518.16 and 258.40

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Solution

The fourth proportional to 345.68, 518.16 and 258.40 is: 387.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    345.68 : 518.16 = 258.40 : x
  2. Step 2: Convert to fraction form
    345.68/518.16 = 258.40/x
  3. Step 3: Cross multiply
    345.68x = 518.16 × 258.40
  4. Step 4: Simplify right side
    345.68x = 133,894.16
  5. Step 5: Solve for x
    x = 133,894.16/345.68
  6. Step 6: Final answer
    x = 387.34

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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.