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Finding the Fourth Proportional to 285.40, 425.71 and 261.81

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Solution

The fourth proportional to 285.40, 425.71 and 261.81 is: 390.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.40 : 425.71 = 261.81 : x
  2. Step 2: Convert to fraction form
    285.40/425.71 = 261.81/x
  3. Step 3: Cross multiply
    285.40x = 425.71 × 261.81
  4. Step 4: Simplify right side
    285.40x = 111,455.46
  5. Step 5: Solve for x
    x = 111,455.46/285.40
  6. Step 6: Final answer
    x = 390.52

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.