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Finding the Fourth Proportional to 903.80, 1,356.40 and 417.20

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Solution

The fourth proportional to 903.80, 1,356.40 and 417.20 is: 626.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    903.80 : 1,356.40 = 417.20 : x
  2. Step 2: Convert to fraction form
    903.80/1,356.40 = 417.20/x
  3. Step 3: Cross multiply
    903.80x = 1,356.40 × 417.20
  4. Step 4: Simplify right side
    903.80x = 565,890.08
  5. Step 5: Solve for x
    x = 565,890.08/903.80
  6. Step 6: Final answer
    x = 626.12

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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.