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Finding the Fourth Proportional to 753.40, 1,039.65 and 438.65

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Solution

The fourth proportional to 753.40, 1,039.65 and 438.65 is: 605.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    753.40 : 1,039.65 = 438.65 : x
  2. Step 2: Convert to fraction form
    753.40/1,039.65 = 438.65/x
  3. Step 3: Cross multiply
    753.40x = 1,039.65 × 438.65
  4. Step 4: Simplify right side
    753.40x = 456,035.08
  5. Step 5: Solve for x
    x = 456,035.08/753.40
  6. Step 6: Final answer
    x = 605.31

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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.