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Finding the Fourth Proportional to 765.71, 1,056.58 and 485.45

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Solution

The fourth proportional to 765.71, 1,056.58 and 485.45 is: 669.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    765.71 : 1,056.58 = 485.45 : x
  2. Step 2: Convert to fraction form
    765.71/1,056.58 = 485.45/x
  3. Step 3: Cross multiply
    765.71x = 1,056.58 × 485.45
  4. Step 4: Simplify right side
    765.71x = 512,914.23
  5. Step 5: Solve for x
    x = 512,914.23/765.71
  6. Step 6: Final answer
    x = 669.86

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.