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Finding the Fourth Proportional to 909.10, 1,254.65 and 687.70

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Solution

The fourth proportional to 909.10, 1,254.65 and 687.70 is: 949.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    909.10 : 1,254.65 = 687.70 : x
  2. Step 2: Convert to fraction form
    909.10/1,254.65 = 687.70/x
  3. Step 3: Cross multiply
    909.10x = 1,254.65 × 687.70
  4. Step 4: Simplify right side
    909.10x = 862,822.81
  5. Step 5: Solve for x
    x = 862,822.81/909.10
  6. Step 6: Final answer
    x = 949.10

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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.