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Finding the Fourth Proportional to 685.95, 1,028.71 and 253

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Solution

The fourth proportional to 685.95, 1,028.71 and 253 is: 379.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.95 : 1,028.71 = 253 : x
  2. Step 2: Convert to fraction form
    685.95/1,028.71 = 253/x
  3. Step 3: Cross multiply
    685.95x = 1,028.71 × 253
  4. Step 4: Simplify right side
    685.95x = 260,263.63
  5. Step 5: Solve for x
    x = 260,263.63/685.95
  6. Step 6: Final answer
    x = 379.42

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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.