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Finding the Fourth Proportional to 209.45, 314.18 and 99.70

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Solution

The fourth proportional to 209.45, 314.18 and 99.70 is: 149.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.45 : 314.18 = 99.70 : x
  2. Step 2: Convert to fraction form
    209.45/314.18 = 99.70/x
  3. Step 3: Cross multiply
    209.45x = 314.18 × 99.70
  4. Step 4: Simplify right side
    209.45x = 31,322.84
  5. Step 5: Solve for x
    x = 31,322.84/209.45
  6. Step 6: Final answer
    x = 149.55

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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.