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Finding the Fourth Proportional to 258.72, 386.64 and 210

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Solution

The fourth proportional to 258.72, 386.64 and 210 is: 313.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.72 : 386.64 = 210 : x
  2. Step 2: Convert to fraction form
    258.72/386.64 = 210/x
  3. Step 3: Cross multiply
    258.72x = 386.64 × 210
  4. Step 4: Simplify right side
    258.72x = 81,194.40
  5. Step 5: Solve for x
    x = 81,194.40/258.72
  6. Step 6: Final answer
    x = 313.83

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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.