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Finding the Fourth Proportional to 756.80, 1,133.76 and 390.68

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Solution

The fourth proportional to 756.80, 1,133.76 and 390.68 is: 585.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    756.80 : 1,133.76 = 390.68 : x
  2. Step 2: Convert to fraction form
    756.80/1,133.76 = 390.68/x
  3. Step 3: Cross multiply
    756.80x = 1,133.76 × 390.68
  4. Step 4: Simplify right side
    756.80x = 442,937.36
  5. Step 5: Solve for x
    x = 442,937.36/756.80
  6. Step 6: Final answer
    x = 585.28

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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.