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Finding the Fourth Proportional to 1,207.50, 1,811.28 and 438

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Solution

The fourth proportional to 1,207.50, 1,811.28 and 438 is: 657.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,207.50 : 1,811.28 = 438 : x
  2. Step 2: Convert to fraction form
    1,207.50/1,811.28 = 438/x
  3. Step 3: Cross multiply
    1,207.50x = 1,811.28 × 438
  4. Step 4: Simplify right side
    1,207.50x = 793,340.64
  5. Step 5: Solve for x
    x = 793,340.64/1,207.50
  6. Step 6: Final answer
    x = 657.01

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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.