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Finding the Fourth Proportional to 287.71, 431.40 and 253.54

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Solution

The fourth proportional to 287.71, 431.40 and 253.54 is: 380.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.71 : 431.40 = 253.54 : x
  2. Step 2: Convert to fraction form
    287.71/431.40 = 253.54/x
  3. Step 3: Cross multiply
    287.71x = 431.40 × 253.54
  4. Step 4: Simplify right side
    287.71x = 109,377.16
  5. Step 5: Solve for x
    x = 109,377.16/287.71
  6. Step 6: Final answer
    x = 380.16

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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.