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Finding the Fourth Proportional to 877.20, 1,212.78 and 803.40

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Solution

The fourth proportional to 877.20, 1,212.78 and 803.40 is: 1,110.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    877.20 : 1,212.78 = 803.40 : x
  2. Step 2: Convert to fraction form
    877.20/1,212.78 = 803.40/x
  3. Step 3: Cross multiply
    877.20x = 1,212.78 × 803.40
  4. Step 4: Simplify right side
    877.20x = 974,347.45
  5. Step 5: Solve for x
    x = 974,347.45/877.20
  6. Step 6: Final answer
    x = 1,110.75

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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.