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Finding the Fourth Proportional to 780.32, 1,170.20 and 347.40

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Solution

The fourth proportional to 780.32, 1,170.20 and 347.40 is: 520.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.32 : 1,170.20 = 347.40 : x
  2. Step 2: Convert to fraction form
    780.32/1,170.20 = 347.40/x
  3. Step 3: Cross multiply
    780.32x = 1,170.20 × 347.40
  4. Step 4: Simplify right side
    780.32x = 406,527.48
  5. Step 5: Solve for x
    x = 406,527.48/780.32
  6. Step 6: Final answer
    x = 520.98

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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.