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Finding the Fourth Proportional to 489.51, 675.72 and 312.57

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Solution

The fourth proportional to 489.51, 675.72 and 312.57 is: 431.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    489.51 : 675.72 = 312.57 : x
  2. Step 2: Convert to fraction form
    489.51/675.72 = 312.57/x
  3. Step 3: Cross multiply
    489.51x = 675.72 × 312.57
  4. Step 4: Simplify right side
    489.51x = 211,209.80
  5. Step 5: Solve for x
    x = 211,209.80/489.51
  6. Step 6: Final answer
    x = 431.47

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.