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Finding the Fourth Proportional to 903.64, 1,355.40 and 287.79

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Solution

The fourth proportional to 903.64, 1,355.40 and 287.79 is: 431.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    903.64 : 1,355.40 = 287.79 : x
  2. Step 2: Convert to fraction form
    903.64/1,355.40 = 287.79/x
  3. Step 3: Cross multiply
    903.64x = 1,355.40 × 287.79
  4. Step 4: Simplify right side
    903.64x = 390,065.48
  5. Step 5: Solve for x
    x = 390,065.48/903.64
  6. Step 6: Final answer
    x = 431.66

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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.