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Finding the Fourth Proportional to 780.65, 1,171.02 and 347.81

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Solution

The fourth proportional to 780.65, 1,171.02 and 347.81 is: 521.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.65 : 1,171.02 = 347.81 : x
  2. Step 2: Convert to fraction form
    780.65/1,171.02 = 347.81/x
  3. Step 3: Cross multiply
    780.65x = 1,171.02 × 347.81
  4. Step 4: Simplify right side
    780.65x = 407,292.47
  5. Step 5: Solve for x
    x = 407,292.47/780.65
  6. Step 6: Final answer
    x = 521.74

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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.