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Finding the Fourth Proportional to 209, 313.67 and 100.87

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Solution

The fourth proportional to 209, 313.67 and 100.87 is: 151.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    209 : 313.67 = 100.87 : x
  2. Step 2: Convert to fraction form
    209/313.67 = 100.87/x
  3. Step 3: Cross multiply
    209x = 313.67 × 100.87
  4. Step 4: Simplify right side
    209x = 31,637.82
  5. Step 5: Solve for x
    x = 31,637.82/209
  6. Step 6: Final answer
    x = 151.38

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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.