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Finding the Fourth Proportional to 780.39, 1,170.62 and 293.40

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Solution

The fourth proportional to 780.39, 1,170.62 and 293.40 is: 440.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.39 : 1,170.62 = 293.40 : x
  2. Step 2: Convert to fraction form
    780.39/1,170.62 = 293.40/x
  3. Step 3: Cross multiply
    780.39x = 1,170.62 × 293.40
  4. Step 4: Simplify right side
    780.39x = 343,463.93
  5. Step 5: Solve for x
    x = 343,463.93/780.39
  6. Step 6: Final answer
    x = 440.12

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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.