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Finding the Fourth Proportional to 780, 1,170.24 and 347.40

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Solution

The fourth proportional to 780, 1,170.24 and 347.40 is: 521.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    780 : 1,170.24 = 347.40 : x
  2. Step 2: Convert to fraction form
    780/1,170.24 = 347.40/x
  3. Step 3: Cross multiply
    780x = 1,170.24 × 347.40
  4. Step 4: Simplify right side
    780x = 406,541.38
  5. Step 5: Solve for x
    x = 406,541.38/780
  6. Step 6: Final answer
    x = 521.21

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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.