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Finding the Fourth Proportional to 785.70, 1,178.40 and 208.62

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Solution

The fourth proportional to 785.70, 1,178.40 and 208.62 is: 312.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    785.70 : 1,178.40 = 208.62 : x
  2. Step 2: Convert to fraction form
    785.70/1,178.40 = 208.62/x
  3. Step 3: Cross multiply
    785.70x = 1,178.40 × 208.62
  4. Step 4: Simplify right side
    785.70x = 245,837.81
  5. Step 5: Solve for x
    x = 245,837.81/785.70
  6. Step 6: Final answer
    x = 312.89

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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.